Sometimes I get somewhere between 44 and 55 FPS even on the main menu (and in-game too) while the UPS stays at 60. The movement is all stuttery, just like when I'm moving my mouse above the buttons of the menu, the button-hightlights appear stuttery too. I have a high-end PC (1080Ti, i7-8700k) and I'm playing on 4K.
However when I'm experiencing this problem usually an alt-tab out and then back fixes the problem. (And if I delete a disabled mod too but I think that just refocuses the window too) (I'm not using any mods, I just have a few installed but disabled)
[0.17.4] Inconsistent performance issues on high-end
Re: [0.17.4] Inconsistent performance issues on high-end
Can you attach a log file?