I've not tried any of these, but the first one is my recommendation, because you can check what your system shows before you follow the advice. The second one is likely an automated version of the first recommendation.
In the answer by visitor, 3+ years ago they say:
type in the terminal
and then in the configuration editor go to: desktop>gnome>session>required_components>windowmanager
in windowmanager you'll find the parameter 'compiz' change it for 'metacity' (without the single quotes), and log-out or reboot, and everything just gonna work fine again. btw happy holidays.
I think that may be worth looking at and trying because you can see if the setting matches, or doesn't.
On my system, if I run gconf-editor and go to the correct tree showing the windowmanager setting I find that it says metacity.
I think this does what the first one does, but via a direct command. My concern is what else is it doing.