B250 BTC 12P doesn't detect cards


I bought a Chinese mobo B250 BTC 12P to see what it is, and it doesn’t detect 6 RX470 cards properly. Cards, risers and everything else is good as it was working in Biostar for many months, only this mobo is new. It has AMI Aptio Bios, and I think I set everything correctly, there is 4G encoding enable etc. So I was trying randomly to connect risers to different PCI-E, as it has 12 PCI-E, and once it detected 5 cards of 6. But then one when I change something, or any. I use an internal graphic card for the monitor because I have no display on GPUS

Does anyone have some experience with this mobo on HiveOs? Any tips?

Allegedly something should be changed in CSM, but this mobo doesn’t have a manual unfortunately and there is no information about it. I don’t know even where to find bios for it …

Here are some print screens from bios Imgur: The magic of the Internet