Random frame drops with empty project

I’m making a game which requires very heavy eye tension on moving objects and each frame drop is an incredible eyesore.
I’m having random frame drops even when opening entirely empty project.
I’ve opened standalone game window, disabled vsync and set max fps to 1200.
I’ve also set up a tick event outputting to log anything below 58 fps.
Turns out once in 1-2 seconds, DeltaTime value is dropping to 0.03-0.04 seconds even with max fps running at 1200.
Same amount of micro freezes happens at 60fps. Given that, around 4-5 frames are getting skipped constantly which is just painful to watch with such eye tensing sidescroller.
I’m using Windows machine.