I successfully ran radxa debian desktop from a uSD card.
I tried the procedure to boot from nvme as per https://wiki.radxa.com/Rockpi4/Linux_system_runs_on_M.2_NVME_SSD
(upgrading bootloader via method 2 and burning the same debian desktop image to the SSD from etcher with an USB adapter) and everything went as described.
I booted the board with the uSD off and the SSD connected, but No Success.
Both green and blue lights are fixed but nothing on the screen.
The board is a Rockpi4B 4GB V.1.4
The SSD is Transcend TS256GMTE220S 256 GB NVMe PCIe Gen3 X4.
Any ideas?