Same issue here. I could disable WiFi, but it’s frustrating that that’s the solution here.
I purchased the db-tronic kit here Raspberry Pi 5 PCIe M.2 NVMe Starter-Kit kaufen – db-tronic, and I’m having the same problems described.
Resorted to booting from SD and connecting the NVNe drive via USB for storage. I might try and disable WiFi and see if that resolves the issue. Unfortunate, as a Cat5 cable will restrict the location of the finished Pi.