Once I had this problem (reinstall drivers), too after flashing with other voltage parameters. After flashing to old bios everything was stable again. So probably you have a bios issue somehow.

Another thing I have figured out, when miner switch off or go to zero after a period of time which is always more or less the same amount of time - go and check temperatures. I have to keep all my cards less then 69°C. If cards go above it will cause failures.

Kind regards sworker