I agree having two boards exhibiting the same situation on the same NIC0 does not point to a hardware malfunctioning; as you implied, it may initially point to a misconfiguration BIOS/firmware-wise. To be 100% sure, based on all of the outlined troubleshooting you have performed, please, let me know the following:
2. What BIOS version did you update the server to?
3. Did you clear the event log (in BIOS) and load the BIOS default settings right after you cleared the CMOS?
1. PBA E40367-305
2. This Update package includes the following system software updates:
System BIOS - 64
BMC Firmware - 00.61
ME Firmware - 1.12
FRUSDR - 16
3. No, I cleared the CMOS using J1B4. That didn't change anything, so I proceeded to do the BIOS update. I skipped the FRU/SDR piece since I really don't know what that does. I did not do anything to the BIOS config after reloading the image. The event log is still there as far as I know. I see an option to clear it, but I don't know how to read it.