@TechUST, Thanks for posting in Q&A. For the setting "Let apps access your location", it lets apps access your location, turn on or off apps you want to Choose which apps can access your precise location.
From your description, it seems the Timezone has been changed back after user manually change it. Based as i know, there's a setting “Configure Time Zone” in Settings Catalog policy to change time zone.
You can go to Intune portal, Devices, find an affected device, check the device configuration applied to it to see if there's such policy applied.
Hope the above information can help.
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