Problem with 3rd party plugin windows becoming transparent

For some reason, Wavelab 10 is randomly making some tool windows, usually 3rd-Party plugins, almost completely transparent. Changing the transparency setting in GLOBAL>DISPLAY makes no difference. For the most part, the Wavelab’s own tool windows do what they’re meant to and DO respond to the transparency adjustment. But not the other windows. My workaround is to save the WORKSPACE layout, shut WL down and then restart. Windows seem to redraw properly. But I think it’s a bug.

I’m running WL 10.0.6 on a Mac with Catalina (OS 10.15.7) and using 3 screens…