Hello Firefox team,
I would like to report a window-switching issue I have observed in Firefox on macOS when multiple Firefox windows are open.
Environment
macOS version: 12.7.6
Firefox version: 156.0.1
Steps to reproduce
Open at least two separate Firefox windows, not just multiple tabs.
Put one of these windows into full-screen mode and work in that window.
Press Command-Tab to switch to another application.
Press Command-Tab again to return to Firefox.
Actual behavior
Firefox does not return me to the full-screen window I was using before switching applications. This interrupts my workflow and makes it difficult to resume working in that window.
I also tried Command + Left Arrow, but this did not bring me back to the full-screen window. I am not sure whether this is the appropriate shortcut for switching between windows on my keyboard layout.
Expected behavior
When switching back to Firefox with Command-Tab, I would expect the previously active Firefox window to regain focus, including when that window is in full-screen mode.
Possible improvements
My preferred solution would be to restore focus to the last active Firefox window while preserving its full-screen state.
An alternative would be an optional setting to exit full-screen mode automatically when switching to another application, if that would make returning to the same window more reliable.
I have only observed this on macOS and have not tested other operating systems. I am also unsure whether this behavior originates in Firefox or in its interaction with macOS Spaces and window management.
Could you investigate whether this is a Firefox issue, or advise whether a macOS setting explains the behavior?
Thank you for your time and your work on Firefox.
