Part of desktop not responding to clicks

Hi all. I’m new to openSUSE in particular and Linux in general. I’m using the latest version of SUSE with GNOME 2.32.1. My problem is that a portion of the upper left area of my desktop does not respond to the mouse. That is: if any given application is running and I click on this area of the desktop, it doesn’t respond to the clicks. I first realized this using tabs in firefox, then I noticed I couldn’t open menus, but I could use the search bar to the right. I attach a link with the image, showing a red rectangle marking the roughly the area I cannot click. Thank you very much.

Do you have the desktop effects enabled? Try disabling this. If this takes care of the problem, enable it again and add the features one by one until it returns.