Do you get this issue while playing the content from LMS or locally as well? Can you check if you get the same issues with previewing the presentation in both Presenter and powerpoint?
The truncated audio is present in both the preview and the published state of the slide. Yet, when I listen to the audio in edit mode, all audio is present. I determined that the slide itself must be corrupted, and since I had the full audio, I added a new slide, copied over all the content, deleted the corrupted slide, and the issue was resolved (I did not do a copy slide). I had to do this with several slides in my presentation. The issue manifested after I had performed a significant amount of edits, removing um’s and ah’s from a 54 minute mp3 across the 32 slides.