I posted in another topic, that 2021.0 or 2021.0.1 will both show the problem. Can you check which 2021 you are using? Or, update to the latest one (2021.1.2)
Mac: https://www.sketchup.com/sketchup/2021/SketchUpPro-dmg
Win: https://www.sketchup.com/sketchup/2021/SketchUpPro-exe