Hyperkey stopped working

I have the hyper key enabled to run Keyboard Maestro macros but it's just stopped working. I have tried re-creating the hyper key; no luck. Has something changed?

(have read through previous threads but they seem to predate the hyperkey function?)

BTT 3.781
OS 12.3.1 (21E258) Monterey

DOH! I'd disabled BTT! Apologies. It's disabled state survived two restarts!