It is Foxconn A7DA-S 3.0.
I can't say for sure whether the port is physically damaged or is it just software issue. On the other machine with the same mobo, there are periods of time when sometimes card is working, sometimes system gets unstable (freezes), but the card is being detected and sometimes card is not being detected at all - I haven't noticed any rule to it though.
I have absolutely no problem on mine, I even wonder if it require the mod I think I had problem because of a bad card.
I used for a while the two yellow slot one in-between without the mod, I suggest you try them as-is. And check all card alone one at the time.
I only send power through the extender at the 5th GPU.