(Firefox Version: 115.7.0esr (64-bit), Mac OS 10.13.6 High Sierra)
1 - Launch a windowed application on the Mac (App1)
2 - Launch Firefox with 2 windows
3 - Set one Firefox window in Full Screen
4 - Switch to the Firefox Full Screen window
5 - Command + Tab to App1
6 - Command + Tab to get back to the Firefox Full Screen Window
Expected Result: The Firefox Full-Screen Window
Actual Result: The Firefox regular Window