5.0.21-sm9 / nv430.40c10.1 / v1264
I also had test with the version SM-4.17.19-20e-a18.20-n430.40-v1257.img.xz
It is the same.

I am testing now with turning off one card per rig which is suspected to made a crash on last reboot, just not sure why and how one card can force all cards to drop hashrate.

It's a little bit strange that this begin to happen at the same time on 3 diffrent accounts, 3 different locations