After routine core package updates on a Rocky Linux 9.6 VPS that require a reboot, the system 'hangs'

SYSTEM INFORMATION
OS type and version Rocky Linux 9.6 (Linux 5.14.0-570.42.2.el9_6.x86_64 on x86_64)
Webmin version 2.510

I have been using Webmin for many years on a variety of Linux and MacOS servers (both VPS and physical (Mac minis)) and have never before experienced this issue. I have been obliged by the decision to cease support for Centos 7 to create a new VPS as an eventual replacement but am currently stuck in the development by the need, after every reboot that is instigated by the core elements update (via Webmin), to resort to the host’s control panel to actually reboot the VPS.

Webmin routinely notifies me of the need to update various packages and after accepting the ‘Update Selected Packages’, the procedure completes with the notice that a package update requires a reboot. Following that action results in a screen to say that the system is rebooting with ‘shutdown -r now’, but it appears simply to shut down the VPS. It appears to me that the notice (“rebooting with …”) is correct, but the action that is instigated is not and that some procedure (part of Webmin, perhaps?) is missing.

I would be grateful for any ideas pointing to a possible solution!