Changes to the RHEL kernel handling class were introduced in RHELC-1685.
The changes resolved the issue for the most parts, but a single scenario was left out/not considered during the development.
That is the original kernel being far ahead of RHEL kernel.
The version comparison only considers these options

• RHEL kernel is the same version as the running original kernel
  • Older version of RHEL kernel gets installed, original removed and RHEL kernel updated to latest
• RHEL kernel has version newer than the running original kernel
  • the whole action finishes at that point without any further changes

With the missing scenario, the kernel is treated as a conflicting version resulting in installation of an older version, but the subsequent update of the package doesn't do anything, since the latest available kernel version got installed prior (during the main transaction).

Discussed briefly with ahosek@redhat.com, this needs to be handled better, ideally comparing available vs. installed queries instead of just comparing already installed versions.