audio not reliably playing during previews

[OpticSugar]

I have a strange problem here.  I'm running After Effects version 23.5.0 (build 52) on an M1 MBP.

I cannot get After Effects to reliably playback audio during my previews.  

• The audio settings were not changed and I believe they are all correct because I *can* hear audio while scrubbing the timeline (while holding the [CMD] key).  
• Also, whenever I attempt to invoke a preview (with either the numeric keypad 0, or . keys, or even the preview palette), I *do* here a fraction of a second blip of audio, then the playback continues in silence.
• Sometimes on rare occasions, it will play audio during a preview, but that is happening less often now.
• This problem does not extend to rendering - rendered files have audio.
• I've tried:
  • clearing all cache
  • restarting After Effects
  • rebooting my computer
  • re-encoding the media that contains the audio (it was an mp4, and I tried encoding it to ProRes 444HQ and replacing it)
  • scouring the web, youtube and this support forum for clues or answers (or even confirmation that this is happening to other people)

I've been dealing with this issue for at least a month now, and it's starting to wear on me to be working on back-to-back projects that require synchronized animation to audio and dialogue, and having to rely only on scrubbing the timeline or rendering tests to see if my animation is timed properly.

If anyone is experiencing something similar, or can point me in the right direction here, it would be greatly appreciated.  I've been using After Effects heavily since the mid-90's and I know my way around, but this has me stumped.

All the best,

Stu

[OpticSugar · Accepted solution]

**SOLVED**

So I systematically tried a bunch of different things to see if I could get clues.  What ended up solving the issue for me was copying all layers of the main composition and pasting them into a fresh new composition.

My conclusion is, it must have been a corrupt composition.  And I've been using an AEP file as a template starting point for many similar projects, which included this comp, so that's probably why the issue has been following me around from project to project.