New Magic Keyboard function keys not working.

Hello,

I'm having an issue with my Macbook Pro w/ Touchbar (2019) and a brand new Magic Keyboard I just purchased (GB Modal if that's useful). I want the FN keys to perform the actions as they would normally (brightness, volume, etc, rather than being treated as standard FN keys).

I've been doing a lot of Googling and can only really see old threads related to this issue, I've tried reconnecting Bluetooth and using just the cable but neither work.

The option for `Use F1, F2, etc. keys as standard function keys` is not available when I open my keyboard settings, I see touch bar settings when my new magic keyboard does not have a touch bar (My MacBook pro does though).

How can I change the functionality of these keys so they work? Happy to answer any more questions if it helps with diagnosing this issue.

Many thanks!