Hi Manjeet Sokhy (Infrassist),
Thank you for posting in the Microsoft Community Forums.
If the device is connected to a domain, a group policy on the domain controller may force a time zone change.
To check group policy settings in Local Policy and Domain Policy
Navigate to the domain and local group policy editors, respectively:
Computer Configuration > Administrative Templates > System > Regional Settings Service.
Check if Restricted User Regional Settings and Restricted System Regional Settings or other related regional settings are disabled. If so, set it to Enabled.
Open Group Policy Editor and navigate to Computer Configuration > Windows Settings > Security Settings > Local Policies > User Rights Assignment.
Locate the policy for “Change Time Zone” and make sure it contains a user or group of users (e.g., “Administrators”).
Open the Service Manager by pressing Win + R and typing services.msc.
Locate the Windows Time service and make sure that its startup type is “Automatic” and that the service is running.
Some third-party time synchronization software may override system settings. Check and disable third-party software that may affect the time settings.
Best regards
Neuvi Jiang