@Jon Thanks for posting in our Q&A.
For this issue, it is by design. Non-administrator users cannot change or interact with the Set time zone automatically setting. The setting is either not visible or is "greyed out" in the Settings app. This is by design as the Set time zone automatically setting is a system wide setting that applies to all user profiles on a machine. Here are some methods can enable this setting, please refer to the following article:
Hope it is helpful.
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