Project won't save Audio track mixer changes

In the latest beta, my audio track mixer is no longer recording level changes for my current project.

It worked for about an hour, but now no adjustments are retained....be it touch, latch or write operation. 

I am able to edit track keyframes in the timeline, and I see the keyframes that were created in the first hour of mixing, but not the ones I tried to add with the track mixer after that.

A new test project does retain track changes.

I tried resetting prefs. The tracks aren't locked. Bug, or am missing something?