Why am I getting horizontal distortions after changing resolution?

I have visual artifacts after changing resolution.

In my menu I have a display for current resolution and after I package the game it opens with 1980x1080 on it’s own and everything is fine.
I use r.SetRes 1920x1080f command and I start getting horizontal distortions when I look around.
The horizontal slicing looks different depending on the refresh rate. At 60 it is more concentrated in one section of the screen, at 144 it is more spread.
This happens in full screen mode from the editor and in the package game as well.
I have tried to capture it with GeForce experience screen recorder but on the video it is barely noticeable.

This issue is the only thing keeping my game from early access release on steam, please help!
Thanks in advance!
engine version 4.20.1