Hi Will,
it does sound like a bad card or a a bad slot to me, I believe that in live fish mode the card should be identified in Device manager, and also with MFT only as "SDR" or "Recovery Mode"
Here's a picture of what a jumper on an HCA should look like :
So I think you might need to try eliminating factors by putting this on a server / slot which is known to work.
Let us know how you progress.
Cheers!