I'm using OMV 4.1.7-1 (Arrakis) and when checking today for the latest available RPM updates for my NAS box, it seems now I have the choice of 2 different versions as outlined with:
user@nasbox:~ $ sudo apt list --upgradable -a
Listing... Done
openmediavault/arrakis,arrakis 4.1.28-1 all [upgradable from: 4.1.27-1]
openmediavault/now 4.1.27-1 all [installed,upgradable to: 4.1.28-1]
Which one shall I choose to update my current platform?