The entire group craps out? Maybe something with EPO in the common panel:group controller? Tug every wire in the group controller and apply slight pressure to any pc board in that same cabinet and see if you getta change in modes. Is there a group status or monitor that shows on a screen what command is being issued at that time? Hopefully not “Automatic”.
Weirdly enough, years ago I had a group of trouble free Swift FUTURA cars that were adversely affected by a recently installed rooftop antenna (leased out rooftop space) that got its signal wires routed in a chase adjacent to the hoist way right where the DPP transducer was positioned on the crosshead. Somehow that close proximity of radio interference caused all kinds of issues.

What is the Fault 10?