Five buttons show in the program monitor: Gang to program monitor, and four transport controls: space, go to previous edit point, go to next edit point, step back one frame, and step forward one frame. When I click on the + button to access other buttons, the only things that show in the button editor are the buttons that are already loaded. I opened up my copy of PP 2021 and the button editor works properly. The trouble is, I have a project I've been working on in PP 2022 that I can't open in PP 2021. Am I missing something obvious about the button editor?
Sorry for the trouble. I solved it by going Window-> Workspaces-> Reset to saved layout. The problem might have happened when I detached the Program Monitor and dragged it to my second monitor screen, then later dragged it back to the original workspace. Something might have happened in that procedure to mess up the button editor. I don't know. Anyway, maybe this will help some other wretch like me.
The buttons you listed sound like the button options for the Reference panel/monitor, which is technically different than the Program panel/monitor, despite it being very similar. But yes, those are the only button options available for that panel.
Not sure how you got the Reference panel out accidentally, but that sounds like what happened.