Is it normal for a Schindler 330 to get a fatal error and require a manual reset /double reboot ever time the elevator goes into battery lowering and properly comes down to the lowest landing and open the doors?
I have one with battery lowering and when I do the cat 1 test it doesn't require a double reboot. I pull the hook, jump the aux contact and it lowers. Put the hook back in and it's fine.
Whats the actual fault info? Maybe your getting some weird unrelated fault that happens when it aux lowers? How old are the batteries in the UPS? if they're more than a couple years old I'd either replace them or at least load test them.