Windows on Mac Air jumping up so the title bar becomes inaccessible

Sometimes when I'm doing something on my Mac, all of the open windows (Firefox, Pages, Telegram, LibreOffice, etc) will move upwards slightly so the title bar of each is partially or completely hidden under the Mac menu bar, and can't be clicked on anymore. I've tried disabling various things on the trackpad in settings and also checked the Zoom settings, but to no avail.

Does anyone know what causes this and how I can turn it off?