Amoré Bay: submerged buttons that activate the pumps have stopped working

[GMO]

Hello world !
For a few days now, the three submerged buttons that activate the pumps on my Amoré Bay spa have stopped working. I can operate the pumps without any issues from the control panel, but not from the seating area. I’ve had this problem before, and it started working again on its own, but I’d like to understand what the issue might be. Each button controls a pump on a different phase (3 phases), so it shouldn’t be a fuse issue. On the control panel, it’s possible to lock certain functions, but to my knowledge, this doesn’t apply to the submerged buttons.
Do you have any idea what could be causing this problem?
Thank you.
GMO