Reboot when older kernel is updated?

[MR ZenWiz]

I'm running Xubuntu 22.04.4 LTS, which reports as:

marbase 6.5.0-45-generic #45~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Mon
Jul 15 16:40:02 UTC 2 x86_64 GNU/Linux
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.04
DISTRIB_CODENAME=jammy
DISTRIB_DESCRIPTION="Ubuntu 22.04.4 LTS"

I received an update to the 22.04 base kernel, 5.15.0-118, but the
updater insists I now have to reboot. The 6.5.0-45 kernel was NOT
updated.

I've seen this happen on every 5.15 kernel update since I upgraded the
kernel to 6.5.

Why does the software updater insist I must reboot to install the
older kernel changes?

TIA.

Mark