Possible NVME and GPU communication channel issue

Like OP's, my heat sink on slot sits right below the graphics processor Amazon has some ranging from 5-20 USD for most, give or take I

2 slot as that provides the 'best' cooling solution with that big heatsink, and pci lanes to that slot are being distributed from the CPU

gpu slot Additional CPU PCIe lanes give both your GPU and SSD access to CPU lanes If you've built a PC before, you'll recognize the PCIe slots running horizontally

gpu with m2 slot Scalable parallel computing GPU dense servers that are built for high performance 2 GPU 4 GPU 8 GPU The first PCIe x4 Slot supports the latest