Trying to figure out how to use the CE Video/audio to make a audio-player with a playlist

Here I use the CE Video/audio with multiple selections:
(I know that it is a feature, that only one audio-player shows up)
Screendump of the backend:

This is the default code for the ce_player.html5 template:

<?php $this->extend('block_searchable'); ?>
<?php $this->block('content'); ?>

  <!-- indexer::stop -->
  <?php if ($this->isVideo): ?>
    <video<?= $this->size ?><?php if ($this->poster): ?> poster="<?= $this->poster ?>" preload="none"<?php endif; ?><?php if ($this->autoplay): ?> autoplay<?php endif; ?> controls>
      <?php foreach ($this->files as $file): ?>
        <source type="<?= $file->mime ?>" src="<?= $file->path ?>" title="<?= $file->title ?>">
      <?php endforeach; ?>
    </video>
  <?php else: ?>
    <audio<?= $this->size ?> preload="none"<?php if ($this->autoplay): ?> autoplay<?php endif; ?> controls>
      <?php foreach ($this->files as $file): ?>
        <source type="<?= $file->mime ?>" src="<?= $file->path ?>" title="<?= $file->title ?>">
      <?php endforeach; ?>
    </audio>
  <?php endif; ?>
  <!-- indexer::continue -->

<?php $this->endblock(); ?>

And here is the player:

Lullaby under the moon.mp3

Moose the Mooche by Charlie Parker_tempo 50.m4a

Moose the Mooche by Charlie Parker_tempo 75.m4a

Moose the Mooche by Charlie Parker_tempo 100.m4a

Steps In Space (S) - Worksheet 1.mp3

straight eighths - solo piano.mp3


Here is the same CE-video/audio, but to inspect $this I made a template (ce_player_playlist.html5) with this code:

<?php $this->extend('block_searchable'); ?>
<?php $this->block('content'); ?>

  <!-- indexer::stop -->
<?php $this->showTemplateVars(); ?>
  <!-- indexer::continue -->

<?php $this->endblock(); ?>

And here's the output:

Array
(
    [id] => 940
    [pid] => 93
    [ptable] => tl_article
    [sorting] => 256
    [tstamp] => 1539278876
    [type] => player
    [headline] => 
    [text] => 
    [addImage] => 
    [singleSRC] => 
    [alt] => 
    [title] => 
    [size] =>  width="" height=""
    [imagemargin] => 
    [imageUrl] => 
    [fullsize] => 
    [caption] => 
    [floating] => above
    [html] => 
    [listtype] => 
    [listitems] => 
    [tableitems] => 
    [summary] => 
    [thead] => 
    [tfoot] => 
    [tleft] => 
    [sortable] => 
    [sortIndex] => 0
    [sortOrder] => ascending
    [mooHeadline] => 
    [mooStyle] => 
    [mooClasses] => 
    [highlight] => 
    [shClass] => 
    [code] => 
    [url] => 
    [target] => 
    [titleText] => 
    [linkTitle] => 
    [embed] => 
    [rel] => 
    [useImage] => 
    [multiSRC] => 
    [orderSRC] => 
    [useHomeDir] => 
    [perRow] => 4
    [perPage] => 0
    [numberOfItems] => 0
    [sortBy] => 
    [galleryTpl] => 
    [customTpl] => ce_player_playlist
    [playerSRC] => a:6:{i:0;s:16:"Zzf桥z:ff";i:1;s:16:"%	";i:2;s:16:"Jg%	";i:3;s:16:"Jw%	";i:4;s:16:"5Z桥z:ff";i:5;s:16:"P%	";}
    [youtube] => 
    [posterSRC] => 
    [playerSize] => a:2:{i:0;s:0:"";i:1;s:0:"";}
    [autoplay] => 
    [sliderDelay] => 0
    [sliderSpeed] => 300
    [sliderStartSlide] => 0
    [sliderContinuous] => 
    [cteAlias] => 0
    [articleAlias] => 0
    [article] => 0
    [form] => 0
    [module] => 0
    [protected] => 
    [groups] => 
    [guests] => 
    [cssID] => 
    [space] => Array
        (
            [0] => 
            [1] => 
        )

    [invisible] => 
    [start] => 
    [stop] => 
    [com_order] => ascending
    [com_perPage] => 0
    [com_moderate] => 
    [com_bbcode] => 
    [com_disableCaptcha] => 
    [com_requireLogin] => 
    [com_template] => com_default
    [rs_columns_large] => 
    [rs_columns_medium] => 
    [rs_columns_small] => 
    [rsce_data] => 
    [rsts_id] => 0
    [rsts_template] => rsts_default
    [rsts_type] => 
    [rsts_direction] => 
    [rsts_random] => 
    [rsts_loop] => 
    [rsts_centerContent] => 
    [rsts_skin] => 
    [rsts_width] => 
    [rsts_height] => 
    [rsts_preloadSlides] => 0
    [rsts_gapSize] => 0%
    [rsts_duration] => 0
    [rsts_autoplay] => 0
    [rsts_videoAutoplay] => 
    [rsts_autoplayRestart] => 0
    [rsts_autoplayProgress] => 
    [rsts_pauseAutoplayOnHover] => 
    [rsts_navType] => 
    [rsts_controls] => 1
    [rsts_scaleMode] => 
    [rsts_imagePosition] => 
    [rsts_deepLinkPrefix] => 
    [rsts_keyboard] => 1
    [rsts_captions] => 1
    [rsts_customSkin] => 
    [rsts_cssPrefix] => 
    [sc_name] => 
    [sc_gap] => 0
    [sc_type] => 
    [sc_gapdefault] => 1
    [sc_equalize] => 
    [sc_color] => 
    [sc_parent] => 0
    [sc_childs] => 
    [sc_sortid] => 0
    [rsts_content_type] => rsts_default
    [rsts_invertControls] => 
    [rsts_thumbs] => 
    [rsts_thumbs_width] => 100%
    [rsts_thumbs_height] => 1x1
    [rsts_thumbs_gapSize] => 
    [rsts_thumbs_duration] => 0
    [rsts_thumbs_scaleMode] => 
    [rsts_thumbs_imagePosition] => 
    [rsts_thumbs_controls] => 1
    [rsts_thumbs_imgSize] => a:3:{i:0;s:2:"50";i:1;s:2:"50";i:2;s:4:"crop";}
    [rsts_thumbs_slideMaxCount] => 0
    [rsts_thumbs_prevNextSteps] => 0
    [rsts_thumbs_visibleArea] => 0
    [rsts_thumbs_visibleAreaMax] => 0
    [rsts_thumbs_slideMinSize] => 50
    [rsts_thumbs_slideMaxSize] => 50
    [rsts_thumbs_rowMaxCount] => 0
    [rsts_thumbs_rowMinSize] => 0
    [rsts_thumbs_rowSlideRatio] => 
    [rsts_slideMaxCount] => 0
    [rsts_prevNextSteps] => 0
    [rsts_visibleArea] => 0
    [rsts_visibleAreaMax] => 0
    [rsts_slideMinSize] => 0
    [rsts_slideMaxSize] => 0
    [rsts_rowMaxCount] => 0
    [rsts_rowMinSize] => 0
    [rsts_rowSlideRatio] => 
    [rsts_combineNavItems] => 1
    [movie_controls] => 
    [movie_preload] => 
    [movie_autoplay] => 
    [movie_loop] => 
    [movie_width] => 
    [movie_height] => 
    [movie_preview] => 
    [movie_webm] => 
    [movie_mp4] => 
    [movie_ogg] => 
    [audio_controls] => 
    [audio_preload] => 
    [audio_autoplay] => 
    [audio_loop] => 
    [audio_webm] => 
    [audio_mp3] => 
    [audio_ogg] => 
    [audio_order] => 
    [movie_order] => 
    [metaIgnore] => 
    [rsts_import_settings] => 
    [rsts_import_settings_from] => 0
    [rsts_thumbControls] => 
    [rsts_visibleAreaAlign] => 50
    [classes] => Array
        (
        )

    [typePrefix] => ce_
    [hl] => h1
    [Template] => Contao\FrontendTemplate Object
        (
            [strBuffer:protected] => 
            [strContentType:protected] => text/html
            [arrData:protected] => Array
 *RECURSION*
            [strTemplate:protected] => ce_player_playlist
            [strParent:protected] => block_searchable
            [strDefault:protected] => 
            [strFormat:protected] => html5
            [strTagEnding:protected] => >
            [arrBlocks:protected] => Array
                (
                )

            [arrBlockNames:protected] => Array
                (
                    [0] => content
                )

            [arrCache:protected] => Array
                (
                )

            [arrObjects:protected] => Array
                (
                    [Config] => Contao\Config Object
                        (
                            [Files:protected] => 
                            [strTop:protected] => 
                            [strBottom:protected] => 
                            [blnIsModified:protected] => 
                            [arrData:protected] => Array
                                (
                                )

                            [arrCache:protected] => Array
                                (
                                )

                        )

                    [Session] => Contao\Session Object
                        (
                            [arrSession:protected] => Array
                                (
                                )

                        )

                    [MadeYourDay\Contao\FrontendHelper] => MadeYourDay\Contao\FrontendHelper Object
                        (
                            [arrCache:protected] => Array
                                (
                                )

                            [arrObjects:protected] => Array
                                (
                                    [Config] => Contao\Config Object
                                        (
                                            [Files:protected] => 
                                            [strTop:protected] => 
                                            [strBottom:protected] => 
                                            [blnIsModified:protected] => 
                                            [arrData:protected] => Array
                                                (
                                                )

                                            [arrCache:protected] => Array
                                                (
                                                )

                                        )

                                    [Session] => Contao\Session Object
                                        (
                                            [arrSession:protected] => Array
                                                (
                                                )

                                        )

                                )

                        )

                )

        )

    [poster] => 
    [isVideo] => 
    [files] => Array
        (
            [0] => Contao\File Object
                (
                    [resFile:protected] => 
                    [strFile:protected] => files/Per/Lyd/Moose the Mooche by Charlie Parker_tempo 100.m4a
                    [strTmp:protected] => 
                    [objModel:protected] => 
                    [arrPathinfo:protected] => Array
                        (
                            [dirname] => /home/stinemic/bifagsklaver.dk/files/Per/Lyd
                            [basename] => Moose the Mooche by Charlie Parker_tempo 100.m4a
                            [extension] => m4a
                            [filename] => Moose the Mooche by Charlie Parker_tempo 100
                        )

                    [arrImageSize:protected] => Array
                        (
                        )

                    [arrImageViewSize:protected] => Array
                        (
                        )

                    [blnDoNotCreate:protected] => 1
                    [arrCache:protected] => Array
                        (
                        )

                    [arrObjects:protected] => Array
                        (
                            [Files] => Contao\Files\Php Object
                                (
                                )

                        )

                    [title] => Moose the Mooche by Charlie Parker_tempo 100.m4a
                )

            [1] => Contao\File Object
                (
                    [resFile:protected] => 
                    [strFile:protected] => files/Per/Lyd/straight eighths - solo piano.mp3
                    [strTmp:protected] => 
                    [objModel:protected] => 
                    [arrPathinfo:protected] => Array
                        (
                            [dirname] => /home/stinemic/bifagsklaver.dk/files/Per/Lyd
                            [basename] => straight eighths - solo piano.mp3
                            [extension] => mp3
                            [filename] => straight eighths - solo piano
                        )

                    [arrImageSize:protected] => Array
                        (
                        )

                    [arrImageViewSize:protected] => Array
                        (
                        )

                    [blnDoNotCreate:protected] => 1
                    [arrCache:protected] => Array
                        (
                        )

                    [arrObjects:protected] => Array
                        (
                            [Files] => Contao\Files\Php Object
                                (
                                )

                        )

                    [title] => 
                )

        )

    [style] => 
    [class] => ce_player
    [inColumn] => main
)

Same CE-video/audio - another template with this code:

<?php $this->extend('block_searchable'); ?>
<?php $this->block('content'); ?>

  <!-- indexer::stop -->
<?php
	foreach($this->files as $file) 
	{ dump($file->path); }
?>
  <!-- indexer::continue -->

<?php $this->endblock(); ?>

gives this output:

string(62) "files/Per/Lyd/Moose the Mooche by Charlie Parker_tempo 100.m4a"
string(47) "files/Per/Lyd/straight eighths - solo piano.mp3"

From the $this->showTemplateVars():
There is nothing in the [multiSRC]
The content in [playerSRC] shows that there are multiple files, but the code is weird:
[playerSRC] => a:6:{i:0;s:16:"Z�z��f桥 �z:ff";i:1;s:16:"������%� �";i:2;s:16:"Jg����%� �";i:3;s:16:"Jw����%� �";i:4;s:16:"5���Z桥 �z:ff";i:5;s:16:"P������%� �";}

Lullaby under the moon.mp3
Moose the Mooche by Charlie Parker_tempo 50.m4a
Moose the Mooche by Charlie Parker_tempo 75.m4a
Moose the Mooche by Charlie Parker_tempo 100.m4a
Steps In Space (S) - Worksheet 1.mp3
straight eighths - solo piano.mp3