Dual display stopped working

Dual Display on my laptop used to work no problem over DP for me. To be honest I’ve done multiple updates since last I checked. But now when I hook up my DP cable, both screens go black and all I can see is the cursor. If I alt-super-f1 I can get to terminal and reboot with cable removed and all is well again… plug cable in and black again… any ideas?

I had a revelation! …I went and turned off compiz and it all works now. Must be some sort of compiz issue.