Is it possible for a AMD gpu to be selecting motherboard to work with? I have a crazy AMD gpu here that refused to work in three different motherboards and only works in one old AMD motherboard, the card is ASUS RX590, crazy but true
first the use eraser on all pcie gpu pin, or teardown the gpu and soak gpu board on detergent around 1hr and try clean it with brush, dry it, put on heater or dry in the sun
if nothing work, use steam solder, re-hot the board at 350C temperature