SSH is always listening on port 22.
Suggesting to hook up a serial console. Best, easiest and cheapest way to debug issues with booting and connectivity since this has to always work.
Panfork is under heavy development/cutting edge so issues are to be expected. Alternative would be to use Rockchip proprietary binary blobs but they seem not to work very well either. On the bottom line nothing Armbian can fix (easily).
Just as a general experience from myself I never had good success on any kind of converter adapters regarding DP, HDMI, DVI or VGA when using with ARM boards. No idea what the cause is. Maybe general lack in drivers to mitigate such configurations...
If somehow possible try to connect native.
Did you leave the microSD in after move? Booting directly from USB is not possible afaik but you can have the boot loader on sd which then boots from USB.
If the system was running flawless before installing OMV and does not after I suggest to blame them 😄.
What armbian-config more or less does only is downloading the omv install script and execute it.
https://github.com/armbian/config/blob/eebfc58c140a34d6e28db5ecbc5faba6b8432ca4/debian-software#L559 ff.