Kodi 17 stuck in windowed mode

Hi all

Recently upgraded my raspberry pi 3 b to 17 (running xbian) but for some reason the GUI is only in windowed mode and it’s greyed out so I can’t change it… So it’s running at 640 * 480

It’s connected to 4 k TV and was able to run ok on v16 but now I can’t at all..

Tried searching everywhere for the solution to no avail

Any ideas, apologies if it’s a noob question.. I’m fairly techie but raspberry pis are fairly new to me…

Any help would be great

Sent from my F8331 (typie typie)