There’s another thread here where the resolution turned out to be bad hardware (bad NICs). Networking down / SFP+ DAC Cable - #24 by matthammond .
But you say you’ve tried a second motherboard. Did that come from 45HL?
What cabling are you using (DAC, optical, transceiver) (SFP+ on both ends or mix SFP/SFP+ port or transceivers), what are you trying to connect to (switch make/model? another PC direct), and what specific errors or symptoms do you have (NIC doesn’t show up, NIC shows up but no IP)? You’re using the Rocky Linux/Houston OS? What does ethtool output look like?