Dell Precision 7560 NVME SSD is not recognized in SSD slot 0

I have a Dell Precision 7560. When I install an MVME SSD in Slot 0, it does not recognize the SSD. I can install the same SSD and Slot 1 or Slot 2 with no problem the SSD is recognized and Slot 1 and Slot 2. I have tried different drives, the particular one I'm working with now is a KIOXIA KBG40ZNS256G. I have checked all the settings in the BIOS. The BIOS shows the SSD and Slot 1 and the SSD in slot 2 but shows SSD slot 0 is empty, even though there is a drive in the slot. I'm assuming either SSD slot zero is defective, or I'm using the wrong type of Drive SSD slot 0 says PCIe 4.0 is it possible that this lot can only recognize a PCIe 4.0 SSD