Disabling changing the time zone does not work in Windows 10

Question

I have a computer which is used by several users. I would like to disable for these users the option of changing the time zone the system uses (both via the "clicking way" as well as via the command line).

I found a way how to do this, there's many articles online always describing the same approach of disabling this option via Local Security Policy. One of such articles showing the approach I am using is here:

https://www.tenforums.com/tutorials/129765-allow-prevent-users-groups-change-time-zone-windows-10-a.html#option2

This approach however does not work for me.

When I disable this option via the Local Security Policy editor (by removing the "Users" group in the "Change the time zone" policy), at first everything works as expected. However, after a couple of days the setting of this policy reverts back and the "Users" can suddenly change the time zone again.

I have no idea what is causing the reverting. I tried to research online first of course, I found some tips, what I observed that is not the cause:

1. restarting the system (during the first couple of days a restart of the system does not result in the "Users" being able to change the time zone)

2. windows update (I paused all the updates in Settings/Update & Security/Windows Update, this also did not work)

3. I don't think there are any conflicting policies (I use the Local Security Policy for two things only. One is disabling the time zone change, another one is blocking running a couple of exe files as described here: https://appuals.com/prevent-users-from-running-specified-windows-applications/ I am definitely not blocking anything that would be related to system time zones. What's also interesting is that the setting of this policy does not change after a couple of days, only the setting of the time zone policy changes.)

4. I am not using any non standard software, so I would say that this is also not a problem.

(I also found some other solutions, but they seem to be relevant rather to network administrators than me as a user of just a single personal machine.)

What I should also note is that I observed this behavior on two different computers of mine, one with Windows 10 as the operating system, and the other one uses Windows 11.