Issue was solved by flashing new BIOS. Assumption is that either upgrade was not 100% or flash is defective. Downgrade from 1.23 to 1.22, should be possible and it is perfectly fine to do that.
Tip for next time: you should try all USB interfaces including the one on the front of APC. If you find one that is active you can try blind BIOS reset to default as we discuss together here Link or use repair channel