Composition going black/blank in latest AE bets

Composition keeps going black in most recent update to AE Beta (24.2.0 build 38). I quit and re-opened, purged cache and memory several times, no luck. Tried different workspaces, no change.

HOWEVER, exact same project looks fine in AE 2024 (non-beta). So the problem is not the project. 

Running latest version of Mac OS 14.1.2.

Thanks!