Aha! Problem solved, I was using the correct shortcut, but an app, Paletro, probably installed for evaluation and then long forgotten, was popping up (obviously uses the same key combo) and showing many Arduino commands and options, leading me to think this was the command palette. Pressing F1 brough up the actual command palette. Thanks so much for helping me figure this out. Uninstalling that thing right now. Thank you everyone for your patience.