Armbian not work on Rockpi 4A

Latest version can’t boot and stop at kernel starting. But radxa’s armbian verion can boot. So what’s differents between 4a & 4b. And how to patch armbian if I want try latest armbian?

Apart from poe & wifi/bt so I thought nothing.
Do you have a serial console dongle ( CH340/ PL2303)? As only way to tell.
Other than that you may have to ask on the Armbian forum.