It doesn't matter what GPU slot you are using if you have an SSD using the Gen 5 capable M2 slot regardless of motherboard. Intel has no dedicated Gen 5 lanes for an SSD. If you are using the purely Gen 4 M2 slots (which are usually chipset on Z790) then you won't have this happen.Der8auer damaged his GPU by heating it up in an effort for fix a "problem' that I don't think he had. Burn this into your head .. my GPU is installed in the slot PICEX16(G5)_1 not (_2) which is the bottom PCIe x16 length slot. PICEX16(G5)_2 is Disabled. The shared bandwidth of the Samsung in M.2_1 only effects PICEX16(G5)_2.
Look and re-read my original post and then look at the page of the manual and if necessary the actual picture I posted of my PC to see for yourself.