yeah i'll fix it, but i'm at work and di this by remote. my mistake for doing this by remote. bios is not modded since its not possible.
second bios is only ULPS on these cards wich reduces hashrate alot so no. It wont even start the cards thats found. so it's sutdown for now

Ok

so i only suspect the pool or a drop of hashrate on the miner. Try with Cast_xmr or xmr-stak.
Check if you have the last 18.3.4 Adrenaline drivers, compute mode enabled. and for Cast_xmr use --algo=1 --ratewatchdog --forcecompute
well, i'm still using the 17.30.1029 beta blockchain driver. although i did not have this problem on xmr with xmr-stak. Is the 18.3.4 driver better?
I havent more little drop hashrate, same results than the blockchain drivers but much more stability with high overclocking or multitasking.
On XMR-stak you can try to :
Down a little the intensity to see if the same.
Configure 2 threads each card (more stable and hashrate)
Set affine_to_cpu : 1 if you are mining with CPU at the same time (more stable)
With my vega i have 2055H/s each card with Cast-xmr.