There's to Much kit out there for them to be able to effectively enforce there regs , so everyone doing pretty much what they want these days , unless someone knows who to complain to, no one cares man , ico don't know Jack what's going on in the grand scheme of things....imo
I think op wants diy fix, system is locked or doesn't know how to default or programme , most of above doesn't make sense (not trade comments), owner would upgrade if paid for , company would install if paid for, and tenant wants to put there own system in? If that's the case, how is other system affecting them?
I would scrap it, time to spend a little on an upgrade , use existing wiring and get something up to date in, will be worth spending the money
Although 9651 is a good panel, personally would go for the g2-12 there are many others
Depends on the panel, some of the old ones do this due to no servicing and life span of the nvm which has or may have lost its programming during the powercycle
Is it a 9800 or 9600 or newer?
Doc probably answer better