Straaange SC2 problem

Been playing SC2 for 10 years, never had a problem before. This machine is nearly 5 years old and its never skipped a beat.

Now all of a sudden, default hotkey for setting control groups will not work.
As in Ctrl-1-0

If I go into the binding settings the key combination works, so the key is working. It just won’t work in game. It is correctly bound and i’ve tried changing it back and forth to no avail. It also seems to be intermittent, which is infurating.

If I use Shift-num or Ctlr-Shift-num they work. So the game is registering the key but just not when its pressed on its own.

Anecdotally there seems to have been other people who have posted this.

Any suggestions?