Right panel losing its contents in Layout mode

[fleecy]

I'm having the weirdest bug in FileMaker 19.3.2.206 on my Intel Mac running Big Sur. 

Switching between Browse and Layout modes eventually leads to the right Pane losing its contents. Sometimes it loses a little, sometimes almost all controls are gone. 

Quitting FIleMaker and relaunching it fixes the issue, until it comes back a few minutes or hours later. Opening a new window, closing the one that has the issue also makes the panel contents come back. 

I tried to empty the FileMaker cache; it doesn't seem to help. 

Any help would be much appreciated to fix this! I tried searching for my issue on these forums, without success. 

F.