I have made a disturbing discovering: the mainboard edge connectors are displaced from the case square holes.
On my old EP(Issue 4) the displacement is about a millimetre, but on my new EP(Issue 6) grows up to almost 1,5mm.
The problem is that old female edge connectors had only single 1mm narrow contacts:
Example: Patkány Edge connector.
While "modern" edge connectors have two contacts per pin, that extend the contact surface more than 1,5mm.
Example: Retrocables RGB Edge connector.
I was struggling my mind trying to figure out why the Patkány refused to work on my new EP, then I have seen the difference on the mainboard position.