I have described my problem 3 times already and have not received an answer.
I have a standard monitor for 1980x1080 and when I start the game in full screen mode, my resolution changes to 1280x720. At the same time, it can be set even lower but not higher. Resolution in the 1980s1080 I get ONLY in borderless mode. But I can not play in borderless mode because there are strong drawdowns of the FPS