Out of the box the sfp card just does not work
The machine sometimes does not boot, just stuck powered off.
The provided power supply seems faulty and might have caused the above problems.
Using a separate power supply and a new pcie sfp card seems to solve the issue but i'm very disappointed i had to lose so much time figuring out what's wrong with something new.
Note: the power supply might have destroyed the sfp card... so who knows what else might have been broken because of it. Either way, off to the junk pile with it and salvaging whatever else i can out of the machine.