The new Micro~~soft~~slop copilot key always sends the following key-sequence when pressed down:
copilot key down: left-shift-down left-meta-down f23-down f23-up left-meta-up left-shift-up
copilot key up: <null>
This means there's no real key-up event when you release the key --> it can't be used (properly) as a modifier like ctrl or alt.
The workaround is to send a pretend key-up event after a time delay, but then you mustn't be too slow / fast when pressing a shortcut.
tldr: AI took a perfectly working modifier key from you.
--- edit ---
Some keyboards apparently do the "right" thing and don't send the whole sequence at once, you can remap those properly with keyd, see: https://github.com/rvaiya/keyd/issues/1025#issuecomment-2971556563 / https://github.com/rvaiya/keyd/issues/825
copilot key down: left-shift-down left-meta-down f23-down
copilot key up: f23-up left-meta-up left-shift-up
this will still break "left-shift + remapped copilot" and "left-meta + remapped copilot", but "RCtrl + letter key" can work as expected
You mean the keylocks and turbo buttons that started in the mid 80s and ended in the early naughties?
Yeah pretty much. Hopefully it would end much sooner than that.