Control-Option-Command-Delete no longer works under Monterey

I've been using this key command for years with ProTools and suddenly in Monterey it no longer works. Somehow this chord is no blocked or reserved by the OS and I would like to get around it.

Any ideas?

Same here!

Latest update to KBM and to Monterey (M1 machine)

there is an OS level key command which is ‘silent delete’ but that’s been around for a while so it shouldn’t be any different. One thing I noticed is that I could assign any two modifiers, but not all three. I also have option-control-command - number pad triggers that aren’t working either so there is something new happening with that ‘chord’ of keys.

I think this is indeed a Monterey thing (rather than anything to do with Keyboard Maestro) as I've just tested and this key ⌃⌥⌘⌫ combination cannot now be set in the App, Better Touch Tool either.
macOS: 12.3.1 (Monterey)
KM Version: 10.1.1

Yes, as far as I can tell this is a new to Monterey issue.

I can also confirm that it seems to be only associated with the Delete key, as you CAN create ⌃⌥⌘clear or ⌃⌥⌘-forward delete.

It's a bit of a drag (because muscle memory... like we are ALL ABOUT muscle memory, right?) but not a game killer.

I have a similar problem with Big Sur. Using Shift-Control-Option-Command-P no longer works on any of my Pro Tools systems with Big Sur. Under Mojave it worked just fine. If I drop the Command key from the sequence it works fine from Big Sur.