Turn off Auto Resizing when moving a program window from one screen to another.

I have a variation on grndvl1's question. Even when I'm not using an external monitor on my new MPB 16" (2021) with Monterey 12.5, the system is constantly resizing (full-screening) my windows without my consent and it is driving me bonkers. I think it's related to the multiple-screen feature because it happens if I move a window to the edge of the screen. When I do this it's usually because I want to create more room for a different window I want to work in -- so when the window I'm trying to push aside instead gets full-screened and blocks everything else out, it is the exact opposite of what I want. This is seriously bumming and stressing me out all the time.

To make matters slightly more confusing, I also have a Macbook Air 2019 that I recently updated to Monterey 12.5 as well. Yet despite the same OS, it does NOT constantly resize my windows. So it appears that what's happening on the MBP isn't some new Apple feature that I have no choice but to accept, but the result of a setting somewhere that I need to change. Do you have any idea what it might be? (I suppose it's conceivable that it's something built into the new MBP that can't be changed, but that seems far-fetched to me.)

Hello grndvl1,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with windows resizing when moving them from one screen to another. Does this occur with specific programs or browsers, or all programs and browsers? Do you have all macOS updates installed?

Update macOS on Mac - Apple Support

Cheers!