I had battled this question for a while, and even tried to hunt though the code to fix it myself. After much searching, I found a patch that was submitted by user Abird. He posted it here: https://www.ads-software.com/support/topic/179225/page/14?replies=531
Probably the easiest way to implement his fix is to copy replace your plugins/audio-player/audio-player.php with the fixed version he posted here:
https://claas.cabird.de/files/audio-player.php.txt
My next questions is, why has this not been included in an official update?