I am using the firmware on 2 machines, but on one of them 2 of the chains got simply hidden and a lot of HW errors appear. Hashrate seems the same as before (18/19Th) even just with 1 chain appearing, and on prohashing it also says its 19Th. I have flashed the original firmware and still just 1 chain appears. Any clue in what is happening and how this can be fixed?

I even have reduced frequency to 400mhz and lowest voltage to see if the chains appeared. Machine was working fine 2 weeks ago.

Also tried to softreset, didn't help. Also PSU is a good and stable one (EVGA)