I found out what was causing the problem. I had installed the latest OS version, Trixie, which it is well documented that OMV doesn’t recognize. I reinstalled with Bookworm and everything is working well and I am very pleased with it.
One issue I do have is that the power on/off button which worked fine when using Trixie now requires a long hold in order turn the system off, not really a problem but it would be good to get the functionality back again.