First, don’t uninstall and reinstall at the first sign of a problem, especially as you say everything else is working. It’s likely an operational issue.
You say you cant see the power window outline. I presume on the UI monitor. The Outline has three modes, off, on for UI and on for UI and grading monitor. Go to the ‘View’ menu and select Window Outline and select off then on.
You should also try, go to any clip, make a new version, on the new version right click on the node editor and select ‘Reset All grades and Nodes’ and then add a new window.
Another test would be to start a new project and see if the same issue exists.
Peter