Problem with screen resolution when using 2 monitors

I have a PC with two monitors, and I don't really understand what causes this error, but it's already annoying me quite a bit.

What happens:
The game launches on the second screen in 720p in the upper left corner of the screen, cropping most of the window and changing the monitor resolution.

Then I use Win+Shift+Left to move the window to the first monitor and select the first screen and 4K resolution in the settings.

 The game returns the resolution of the second monitor to normal and changes the first monitor to 768p.

After that, I have to go back into the settings and set 4K, and then everything starts working properly.