I've updated the BIOS and iDrac with the files you linked, and cleared NVRAM. Oddly, when I went to revert the card back to stock dell firmware to try again, it detected as a D1 revision instead of a B0 revision. I cancelled the rollback, because it didn't match up with what I saw earlier. Going through the whole process again (without reverting), I encountered the exact same behavior. Perhaps updating the BIOS changed how the card was detected or something? If I revert back to the D1 firmware and then follow the D1 guide, would that brick the card if it was in fact a B0 revision and the software isn't detecting it correctly?That's really, really strange - the card is getting crossflashed to the correct PCI vendor and sub-vendor IDs, so no problem there. At this point I'm not sure what else to try other than:
ensure your BIOS is at v2.9.0, and your idrac is at v2.65.65.65 - very important. You can easily update both through the idrac web UI under idrac settings > update/rollback. There's an upload form, just upload these two exe files and it will recognize them as firmware updates, and idrac will install them without needing to boot any OS (they are for R720XD as you mentioned in your other post):
idrac: https://dl.dell.com/FOLDER06110107M...roller_Firmware_0GHF4_WN64_2.65.65.65_A00.EXE
bios: https://dl.dell.com/FOLDER05981274M/1/BIOS_8P8WX_WN64_2.9.0.EXE
After that, try again after both are fully updated. If still no luck, you need to open it and find the NVRAM_CLR jumper - move the jumper to pins 2-3 instead of 1-2 where it is by default, and leave it for ten seconds, then move it back. then power the server back on. This will reset the BIOS/UEFI settings more thoroughly than a simple "reset to defaults" will in the bios menu. One other member at least in this thread had this solve the same problem:
Thank you for your help.