They might not be fake.
It's trivial in China to copy damn near anything.
Jlpcb might have thrown out a couple, leaked gerbers somehow, or pulled a fast one on you.

Or someone could have copied it based on the pics you posted. Most of the wiring is pretty standard.
The dimensions are known. They have a billion boardviews.

Sorry.

Man, that's seriously shady. I mean, is it POSSIBLE that someone could take your schematic and BOM, and build their own board layout from it (possibly with AI assistance)? Given that this is 3 "different" sellers all shipping from the same city, with the same exact ad and the same amount of "inventory", I'm definitely not saying that THIS person did that (these 3 accounts are CLEARLY the same person). It seems like that EISA connector would be hard to source, given how obsolete it is.