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.
Slightly off-topic but interesting. Quite a while ago I tested a 16:10 monitor with 1920x1200 resolution on the Station P1 I could not get to work with other kernels than legacy 4.4.y. Which branch did you build against? current or edge?