Using Firefox 135 on macOS 15.3.1, if I switch to the Finder and then back to Firefox, all the Firefox menus appear to disappear - in fact the font colour has changed to white, and they are nearly invisible against the grey menu bar. If I then click on the Desktop to switch back to the Finder, and then on the Firefox window, the menus reappear in their usual black. I do not use the system's dark mode and have the appearance theme set to System theme - auto. This happens two or three times a day, but not every single time I switch apps. It was happening on 15.3 as well, and I think it first appeared with the previous update to Firefox. No big deal, but a curiosity.
