Hi PointC and Jonathan,
@JonathanThe alerts on DragEnd event occurs correctly. I have created one sample and it has the same issue. As this sample has a audio file I have not created it with CodePen. I hope its fine.
Please extract the zip and run the test.html in both desktop browser and on iPad Safari browser. On the desktop browser the when you drag and release the arrow image, you can hear a audio, however if you launch it on Safari on iPad then you cannot hear that sound.
audio_issue.zip