I ran into a specific problem because after looking through this section looking for answers, I didn't find anyone else with a similar problem.
Previously, it seemed to be that my game was running in full screen mode, as evidenced by the brightness in the game itself, which was higher than on my desktop. (I might be wrong) However, recently it feels like it switched to windowed mode on its own.
Also, if I click on the "Next turn" button, instead of showing me where and how different units are moving, the game just freezes after a couple of seconds. A similar situation arises during battles between units if the battle lasts more than two or three seconds. At the same time, my brightness changes to the one that in theory should be in full-screen mode, and the mouse cursor changes to loading. However, this freeze is not permanent, it brings me back to the game again around the same time when all the units of other civ`s should have finished their movement. But anyway, It really interferes with play and literally pulls you out of immersion.