Same problem here and more.
Working with Cura 4.8 on Big Sur 11.1
- I can't select an object
- Preview doesn't work. Sometimes I get a build plate with the object shadow, or else it's a white screen.
- Monitor doesn't work.
- I have 2 printers and they have different names, but in the drop down there is only one name, twice.
- Cura can't retrieve the materials loaded.
After restarting Cura some problems can be gone for some time, but suddenly they are all back.