U2419H, screen flickering, #3

I have a similar issue with my U2419H.

4 weeks after purchase I also noticed a screen flickering.
It started appearing randomly and disappears when I do one of the following:
- changing monitor refresh rate to 29Hz for 10 seconds
- doing factory reset
- plug out display cable, plug it in again

I have brightness set to 38% and contrast to 58%, so you can say that my config is darker comparing to default setting

Recently it started to appear much more often.

I tried DP cable, also 2 different HDMI cables.
Tried to install/uninstall monitor driver and dell display manager
The issue even persists in Windows Safe Mode, so it doesn't look like a problem with drivers.

The video card is RX Vega 56.

Currently it seems like there are only two things I can do:

- Try it with different video card
- Warranty service