I'm having this problem I can simply only describe visually, like so:
Googling the error came to nothing. lightdm also exhibits this behavior but switches back and forth from this to the proper display as I click on things. I remember cleaning out lightdm entirely and reinstalling it but this problem came back again. If I launch LXDE this doesn't happen but I want to keep using Xfce. How can I fix this?
xrandr
and looked for the "normal" res on the output?