The successful install of update kernel but running the old one and the mismatch output of
uname -r
rpm -qa kernel-ml*
Looks “similar” to my problem in below and the hint of @pedro help me out.
https://forums.rockylinux.org/t/problem-in-upgrade-to-4-18-0-425-3-1-el8-x86-64/7903/26
Hope that apart from “fighting” with the grub, @pedro hint may help you also.