4.12 low and unstable FPS

I installed 4.12 yesterday and converted a copy of a project from 4.11 to 4.12 that I’m hoping to put on the marketplace when I’m finished. In 4.11 i was getting a perfect 60fps but in 4.12 I’m getting a very unstable 30fps, sometimes dropping well below 10fps. The problem seems to be made worse by hitting F11 to go full screen in both edit mode and play. I also tried launching a 3rd person project in 4.12 to see what kind of fps i get in the demo level and I’m getting about 40fps, i should have no prob getting 60fps. Everything’s set to “Epic” in the scalability settings but this never caused a prob for me in older versions. Can anyone shed some light into what’s going on here?

I got the same problem, does your UI flicker too at random when you are using the drop-down menus?