How to fix flickering background in unity?

Question

Unity

https://ru.files.fm/f/pa9hnx38 - here is a video of what exactly is going on (look at the left side of the screen. The background will flicker there from time to time). In short: I'm making a game and I use tilemaps to generate the level, and cinemachine for the camera. There was a problem: when I start the scene, the part of the screen near the camera starts to flicker. Help pliiiiiz)))). Thank you very much)