Gpu doesn’t work on primary PCIe , only secondary

[plig88luthier]

Hello ,,,, I have a problem with my pc ,,,, before 3 months I buy a XFX RX 580 8gb ,,, everything is fine , and I play pubg perfectly ,,, before a 2 weeks I flash the bios and I bricked the gpu , so I gave back to company and I wait to send me back ( work) ... yesterday I buy another rx 580 sapphire nitro + 8gb used ,,,,, I put in primary slot pcie , and no output ,, only work the igpu from me cpu ,,,,I change the slot to 2nd pcie and work , but when I try to play pubg , it crashed ,,,,, why it doesnt work in primary slot ??? I put and other gpus, gtx -660 -970 and 1080 .... and work perfectly but the primary slot with sapphire doesn’t work only in 2nd ...... I search for reason and everyone says to turn the onboad graphics to pcie ,,,, it’s not this , I try ,,,,,

My system is

Asus b85 trooper ( latest bios )
2 x 4 gb Corsair vegeance 1600
Intel i7 4790k
Rx 580 sapphire nitro + 8gb
Zalman psu 700 watt bronze


Please help me

 

[plig88luthier]

I forgot to say ,,,, this Sapphire RX 580 use for minining ,,,, maybe the card work only in second slot ???? I don’t know