One other thing the H710 has plenty of cooling ?
These RAID and also the HBA's controllers are heaters and will very quickly get hot
They are designed to go into rack enclores with forced cooling from front to back
Back in the day in my tower case I glued on a fan to the heasink as controllers in the 70+deg is not good
Batteries don't like getting hot either
Latest FW for H710p here
https://downloads.dell.com/FOLDER04455766M/1/SAS-RAID_Firmware_9MHJ5_WN64_21.3.5-0002_A09.EXE
Ofcourse won't do you any good if you can't boot
But your FW is possibly only one iteration older than latest
Maybe a factory reset with the Mobo BIOS, take battery out for a minute or so
Can you play with PCIe slots in the BIOS, ie disable or other settings ?
Maybe force PCIe Gen 3 or even 2 on that slot if Mobo supports Gen 4