Hi I write to you to ask for help because I'm going crazy.

I modified the bios of a Sapphire Rx570 8gb Nitro +, with the latest drivers and with the appropriate straps to reach a dignified hashrate. Start the mining, everything is perfect (29 Mh/s)
I turn off the pc, I mount the card on the rig (then on another pc, but with the same config), and now the card even has a hashrate less than the original, now it goes to 18Mh/s 
I tried to modgle it again on the rig and it's as if there was no mod, but if polaris control the bios is the modified one! Help me ,tyia!