I’ve tried restarting, unplugging/restarting, disconnecting camera, disconnecting/reconnecting panel, loosening screws on panel.
Cant seem to get buttons on panel to work.
This occurs at the point when you first start and it gives you the message about reading the manual and then the “Next” appears on screen.
Submitted ticket but if anyone has any other suggestions
Same problem with mine a few months ago. Support didn’t know what the problem was, so I asked for a replacement panel. Once installed all was OK.
Ditto with me this week, New P1S, down button didn’t work well on the controller, just got a replacement, works great now
I just returned and exchanged. All is working now
Hello, I had the same problem a few days ago with my new P1S in December 2024.
I am answering cause I solved the problem and seems still an issue at P1S.
I located non correct connected pins at the cable. The cable is pinned at the plug and fixed with glue. Nevertheless some pins was pushed out when the cable was connected/pressed by me at the screen board. Therefore the buttons didn’t work.
After inspecting and locating the problem I pushed the pins back into the plug.
Problem solved. Buttons working! 
Probably this hint can help somebody. Not necessary to send any part back.
Axel
same for me, removed screen following official bambu wiki for the screen removal.
turns out connector came unplugged a bit. probelm resolved after making sure it was plugged in all the way.
same problem I had.
didn’t really see anything loose, but I disconnected it and reconnected it and its working just fine now.