Ok so I know this is old HW but it is what I've got. It's a Fatality z97x killer board. I have 7 sata drives and 1 M.2 drive. I have 3 of the drives using onboard sata controllers and then I have a 4 port hba for the other 4.

This config has been working just fine for several years. I finally got to the point I needed to expand some drive space. So I ordered the exact came HBA and put it in my next slot and put in the new drive. Upon doing so I boot to a flashing cursor. If I pull the new drive of but leave the HBA in it will boot so its something with that drive. Tried a different drive and it does the same thing. Really need the space. Anybody have any suggestions?

Did you check that the flash drive is still the first boot device in the BIOS?

Sorry, I forgot to list that. Yes, the flash drive is listed as the first boot device and there’s a UFEI flash drive listed as the second boot device and I disabled the third one just to be sure.

Then it looks like a compatibility issue with the board, or a BIOS issue, look for a update

Ok but with no drive attached system still posts and boots into Unraid just fine and that is with both hba’s installed. It is also the exact same hba board as the first one (amazon reorder) I can understand it might have a different firmware but it would be newer so would assume it should work.

Not trying to argue, just trying to ensure what I’m telling you is as accurate as possible

https://a.co/d/08Rkh3w

This is the hba

The extra drive may still be problem, some BIOS have a limit, a possible option would be to delete the HBA BIOS, if there's one, since that's not needed for Unraid, some boards also have a BIOS option to not allow the BIOS, usually called show OPT BOOT ROM or similar.

Unfortunately, on this one here there’s no limitations as to the number of drives and there’s nothing I can see as far as a bios on these so nothing I can see to disable :-(