Camera bounds glitches

hello, I’m a beginner and I followed a tutorial to make camera boundaries so the blue background of the unity editor doesn’t appear. However I have two issues, the first one is that the camera boundaries (the coordinates) keep adjusting on their own when I open the maximized game view or change the scene window size. How do I know what size will be suitable when I build the game?

The second issue is, right after I wrote the boundaries script the player started freaking out and shaking while moving (I can take a video of this if you need).

Please help if you can with explanation, thx.