I have been having this issue and am currently running 11.something new. I have read through the posts and have tried restarting the device, no dice.
Contacted Apple support and got an answer to the effect that the keyboard is not an apple device and since it is not an Apple device they will not support it. Makes sense on why the issue may not be getting full support here on this forum or when people call. I do know that Apple does not know who made the device under their name since it is named the Apple Smart Keyboard...kinda confusing.
Apple, can we get the name of the supplier, manufacturer, contractor, or elves that made the keyboard so we can start getting a resolution? Or, stand behind your “named” product and give the discussion some recognition beyond the usual IT “please turn the device off and on” or “is the device plugged in.”
Apologies if my grammar is off, high school diploma...
Matt