PCIe x16 either 'Not Present' or 'error' with x0 Gen1
So I bought Biostar TB250-BTC PRO motherboard, updated BIOS to the newest one and there is a PCI-E check before everything loads. Pretty screen with dispalyed every pci-e slot and it's status- working/none/error.
I don't have anything plugged into x16 slot, but it tells me there is an error with this slot. Plugging card into the slot, it also shows error, but if I change link speed from 'Auto' to 'Gen2' or 'Gen1', instead it tells that there is no card ('none' shows up). Apart from that x16 slot, every pci-e x1 works fine, and the x16 slot was tested on 3 GPUs, none of them worked on this slot, but worked on others.
Any idea? I literally tried everything. Cards also doesn't come up on Windows.