Stuck key on thumb row (space)

My space (+fn = enter) key is stuck on. It will switch between the two inputs depending on the function key, and will pause input (but remain lit up as pressed in an LED mode that shows activity) until hit again. This ends up with space or enter being repeated until any other key is pressed, and will repeat again once tapped again. Started one day, and hasn’t changed since.

Have cleaned with ethanol a number of times, that hasn’t changed anything.

Can’t enter test mode, seems it’s interrupting that key sequence. Checked sketch, test mode is still included, and re-flashing doesn’t fix it either.

Haven’t heard back from the support email address yet, but hoping I don’t have to replace the keyswitch. Anyone have any suggestions to try in the meantime?