I've tried 20 different sd cards and 2 different pi's. Same result.
Reyling on this part of the story if you used Etcher and checked download integrity manually then no help is possible (it's then a miracle)
On first attempt I had no right to do anything.. Including updating.
Neither from the web control panel, nor from console logged in as root..
Second to every attempt after it simply doesn't boot.
Reyling on this part of the story (burned the image once and then trying to boot this image subsequently) most probably something went wrong on first boot. On the RPi image on first boot the installation will be updated to latest OMV and Linux versions, that includes both bootloader and kernel. If something goes wrong in this process (eg. a reboot forced manually) thr Raspberry will be bricked (not booting any more).
So basically it's now what I've written already twice: checking download integrity and burning image again with Etcher, then waiting for the RPi finishing the installation followed by a reboot.