rx vega 56 not recognized on pcie 3.0

[bichedeflex]

hey guys , i ask your wisdom here
my rx vega 56 ( rog strix ) is not recognised on pcie 3.0 setup , it turns on , lights and fans , but not detected through bios hardware or anything

when plugged to a system on pcie 2.0 port 4x , it works very fine ((and draws a lot of power btw)
( furmark) (amd system)
but on my recent build intel i9 pcie 3.0 , system boots but no show for the vega .. ( tried tweaking bios for pcie 2.0 but no options

gpu bios is locked , updated it , dowgraded it , nothing does improve

gpu is in super condition
only thing that could bother is this little mark on a lane ( lanes have all been tested with multimeter)


im guessing that cpu (in charge of pcie 3.0 ) doesnt recognise pcie 3 , gpu chip problem ? 

any ideas welcome , cant understand the prob , and asus CS are not supportive at all , nore would i recommend them , this card if im right with serial number is from 2018 .. but out of warranty
..