(Cycles) Render region not updating in camera mode

No idea what I did but when I rotate the camera around in rendered mode (Cycles) the rendered part doesn’t update interactively.
The simple shaded parts are updated while the rendered part just stays put until I stop moving the camera, then it starts updating… same thing if I try to move objects around. In Perspective mode things update normally.
Any ideas how to fix this?

Actually it kinda updates but only every 1-2 seconds, where as other views update constantly…
Also if I open another scene things are back to normal so I guess I changed some setting or something.