Previews not working intermittently (plus Toggle Mask and Shape Path Visibility issues)

I've been noticing for the last few weeks that sometimes when I try to preview my composition, it just won't play and the playhead doesn't move. It doesn't matter what's in the comp (video, shape, etc.) it just refuses to play.

Things I tried that didn't work:

- Murcury Software Only

- Murcury GPU Acceleration (CUDA)

- Purge all memory and disk cache

- Every setting on the preview player

- Audio Hardware properly set to speakers

A weird thing I noticed when it gets into this state is the "Toggle Mask and Shape Path Visibility" will  toggle on and off depending where I click on the screen. It could be on, and then when I click on Premiere Pro on the other monitor, it will suddenly toggle off. Then I click back into After Effects and it's still off until I actually click on the timeline to move the playhead... suddenly it will toggle back on.

The only thing that works is closing and re-opening the project. But it eventually goes back into that weird state whete ot can't play and the toggle mask randomly turns off and on.

I updated to the latest version but it didn't fix it.

Anybody else have this problem?