What is the correct kernel image for latest OMV 4.x?

Hello,

I have to VMs which are supposed to be running the same Arrakis version but not sure why they have different kernel versions despite they have the same apt/source.list.d/ files.

One runs with 4.9.0-8-amd64 and the other with 4.19.0-0.bpo.4-amd64

dpkg -l | grep openm
ii libopenmpt0:amd64 0.2.7386~beta20.3-3+deb9u3 amd64 module music library based on OpenMPT -- shared library
iU openmediavault 4.1.22-1 all openmediavault - The open network attached storage solution
ii openmediavault-keyring 1.0 all GnuPG archive keys of the OpenMediaVault archive
ic openmediavault-omvextrasorg 4.1.15 all OMV-Extras.org Package Repositories for OpenMediaVault

Is there any command to force an OMV upgrade or check? or should I force the installation of one of the kernels?

MERCI
XabiX

Thank you. This was new for me, and I will therefore activate it as it seems a better option. Not sure if this will change anything but at least the kernel seems newer

merci and have a good weekend