Been getting this on Win 11 too, also when i try to change artwork the dialog box in windows won’t let me select an image and the only work around is to close plex and reopen it
Perform the thorough uninstallation by
removing “Plex” using the Apps control panel
empty out the data folder in C:\Users\<yourusername>\AppData\Local\Plex
Did you find an answer to this? I am having the same issue. After the server question, it asks “Customize your Media?”, so it resets the left navigation column and my whole screen every time.
This was asked here as well (which is how I found your post).