Another clue that may help QA. I am using a Studio Display with my laptop (see specs in a prior post from me on this thread). I had the game resolution set to 2560x1440 and the render scale set to 100%. With these settings, I always get UI flickering, most commonly when rapidly clicking on the left or right mouse buttons. I was using this because it looked fine and also gave me a good balance of performance with almost no fans. I changed the resolution to be the native resolution (5120x2880) and set the render scale to 50%. I cannot reproduce the flickering under these settings. In my case, it seems to have something to do with the resolution not being native. Just thought I would pass this along in case it provides a clue. Funny that I stumbled across this when I was playing the game on the laptop screen while chilling on the sofa. I didn’t see the same flickering on the laptop itself (mainly because it was running at native res).
Note that I can get the frame rate to drop by 10-20 FPS by rapidly clicking the mouse (in particular the right mouse button) regardless of what the graphics settings are (as others have mentioned in this thread).
1/5: I noticed I had a typo. Should have said “cannot” above, instead of “can”. 