How do I format an HP-48GX FRAM Card?

[rprosperi]

Port-1 and Port-2 in a GX are indeed different, this is how Port-2 can use bank-switching to access up to 32 128KB banks, so it's not totally surprising to see different behavior.

Was the FRAM card intended to only be used in Port-1, or is that simply how you had your GX set up?

Looking more and more like the card is defective...

Have you tried contacting the person that sold the card? Often, years later, that person has moved on and isn't reachable, but it's certainly worth a try.