macos external USB keyboard command key not working I have a reliable external keyboard that worked normally with a macbook pro (2018). I've upgraded to a new macbook air and the command key isn't working with the external keyboard. For example I can't use any keyboard shortcuts such as ⌘-space for spotlight. It appears to be just the command key.
Other examples:

⌘C, ⌘V not working
⌘, for preferences not working
Menu bar items (such as Edit &gt; Copy) have the ⌘C greyed out instead of black font.
Other keys work normally: tab, Enter, Ctrl-L (for clearing terminal screen for example).
Laptop keyboard working fine.

Attempted (failed) fixes:

Reboot
Reset SMC (also PRAM, NVRAM)
Check USB connections on different ports
Delete Libarary Prefs com.apple.HIToolbox.plist
Repeat the keyboard detection (Prefs &gt; Keyboard &gt; Change Keyboard Type...)

Keyboard type:
Coolermaster Quicksight Rapid-i mechanical keyboard. I have used it successfully with work laptops (windows and macbook pro) as well as an iMac (2012).
Solution: Switch Modifier Key Assignment
For some reason the new macbook is detecting the Command ⌘ key as Alt and vice-versa.
Preferences &gt; Keyboard &gt; Modifier Keys... and switch the ⌘ and Alt keys.
Now it works. This was a painful experience so I'm sharing what I wish I had found online. I didn't discover that the command key was actually working until troubleshooting on https://keyboardchecker.com.
The Menu list shortcuts are still greyed out. I don't have a solution for this, but its cosmetic as the shortcuts still work, even ones I assign in keyboard prefs.