VDO module does not load (again) under kernel 5.14.0-570.25.1.el9_6.x86_64

Thanks, this did the trick for the moment.

Acknowledged in upstream, fix scheduled for beginning of August:

the release of the kmod-kvdo-8.2.5.14 rpm fixe the problem (at least until the next rhel release). At this date install this version instead of recompile the previous one.