Currently I can no longer make simple surfaces. For example, when making a circle, an extra rectangle appears. When making a rectangle, an irregular rectangle appears. And when I click on the surfaces, it appears to be multiple surfaces. Switching the application (Sketchup Pro 2021) on and off or clean all does not help ???
Start with the basics of SketchUp at Campus - learn.sketchup.com, especially tags and geometry.
Turn on all tags and learn about grouping loose geometry and assign tags to groups and components, not to raw geometry.
Your screenshot shows that you have edges turned off, so you probably have hidden edges all over the place that are interacting with your shapes. Which is why @mihai.s is telling you to take the time to learn about tags and grouping etc…
and is that the cracked 2021 version, that has issues.
You are right. Edges was turned off. Stupid, forgot about that. Now removed all the hidden geometry. Thanks.