External NVMe Sabrent SSD not recognised by Catalina Macbook Pro 16" over USB-C, only USB-A

I had the same issue. You need an NVME enclosure that has the ASM2362 chipset and not the Jmicron JMS583 chipset. All NVmE enclosure with that chipset have compatibility issues on the Macbook Pro 16 only and maybe the newer Macbook Pro 13. My older Macbook pro has no issues. Ugreen NVME enclosure on Amazon has the ASM2362 chipset which work well on the Macbook pro 16. Hopefully Apple fixes it or Jmicron comes out with a patch. Same issue with Big Sur as well.