Browsers not reducing in size on clicking middle button

I have three browsers Vivaldi, Chrome and Firefox. In the top right corner are 3 buttons
the left one closes the browser to the panel, the right one closes down the browser and the middle one will expand the browser to full screen but it does not work in reverse to reduce the browser to its previous smaller state.

I know that this is an old thread, but:

Could you try dragging the corners of the window to match your preferred side? I had this issue with Chromium but didn't with Firefox and Vivaldi nor Opera.

why drag the corners if you can "ctrl + alt + middle-click + drag" in any part of the window ? :slight_smile: