Update:
When I'm clicking the rectangle a new note is created. I guess by mistake a shortcut for new notes have been activated?
How to solve it:
macOS Monterey introduces a Quick Note feature that's designed to give you quick access to a fresh note in the built-in Notes app if you need to jot down some ideas in a hurry. Quick Note is enabled by default and can be accessed by mousing over the bottom right hand corner of your Mac, but if...
www.macrumors.com
Go to settings and mission control. Then hot corners and deactivate quick note.