Audio drops out at end of timeline v20 Build 38

Having an issue where audio drops out at the end of the timeline. Waveforms are still there, mixer shows audio levels continuing, I have no effects, no keyframes, no dissolves just suddenly no sound through speakers and Bus 1 stops receiving the signal. I've tried re-pasting the original clips, pasting in other clips, I've worked through settings etc. to no avail. If I paste a different clip at the end of the timeline that also has no sound.

The spot where the dropout is happening seems to correspond to an earlier timeline length I was working with in the last build of version 20. Once I go past that timecode, audio is gone.

Any ideas? I have the premiere screening of this project coming up and I'm flummoxed.

Thanks!!
Niels

So the Track meters are moving, but the Bus meters are not?

Automation, maybe?