Any 16.9 through 16.11 driver should work. If driver checks bios, it will fail 100% of the time and never work.
If it works sometimes, then check PSU, voltages, clocks, and temps.
Your clocks/volts should be fine, you can try lowering intensity, or using 8.0, or Ethereum.
Also, try reseating cards in risers, or swap risers.
I think my board is problem (Asrock Z97 fatal1ty killer), or just last PCIe x1 slot, now conected 1-5 and last one (6) left free (before it was second free, x16). And all working for now.