Cursor slows to crawl, sound disappears, track plug-in automation gone

Gotta weird problem with Cubase Pro 11 that started a few days ago. Playing thru a track, the cursor suddenly grinds to a crawl and the music stops. It’s irrecoverable, but I can still save the project and quit out. Things are fine upon restart—except that automation has been disabled for plug-ins, and I have to manually click the ‘R’ button to re-enable. The problem is intermittent, happens at random locations in the song, and I can’t tie it to anything in particular. What is happening!?

Me: Cubase 11 Pro user, Mac OS Catalina 10.15.7


I haven’t seen this. Make sure your plug-ins are up-to-date, please.

What plug-ins do you use, please?