That would certainly indicate to me that the issue is with the card, considering it works fine with the H310 and they'd be using the same slot. The only thing I'd be able to suggest at this point is to replace the H710P with another.
Hello,   I have an Dell R520 server which now contains an Perc H310 controller on the motherboard, I bought an Perc H710P which should be compatible with this server. However when I switch the controllers I get : PCIe Training Error: Integrated RAID I have tried a lot of things  to get this to work, and am running out of options. Am I missing something simple? kind regards, Martijn
Dell R520 replacing Perc H310 with Perc H710p