Comment 3 for bug 2063235

The window behaves differently when dragged, I think. I tried lifting the mouse to rule out any dragging movement, but the window still resizes. I'll attach a video to illustrate. Description:
The window is maximized at the start of the video. I move the mouse pointer to the menu bar, physically lift the mouse and click one time. I then maximize the window again by double clicking, and retry the single click one more time. Same result. The position the window goes to indicates that it is not actually being dragged.

I see now that this only happens in certain apps. Among them Brave Browser and JupyterLab Desktop. Brave Browser has an option to "Use system title bar and borders", and when this is active, the resizing does not happen when clicking the system title bar.