the object masking tool is failing in the most recent Beta update. It makes the initial mask ok, but won't select forward and backward anymore. Just keeps spinning

I literally updated to the most recent beta today (I was using the previous Beta, so all STILL beta)

I tracked and masked multiple items using the mask tool.  It worked great.  

Newest update:  still masks people/items/things pretty well, but it won’t “track” them forwards and backwards.  It gets stuck in thinking (spinning) and never resolves.  The previous beta did this in seconds!