Night Shift from sunset to sunrise requires location

This is an answer, not a question, as the original thread seems to have been locked. Here's the original question:

When I go to System Preferences > Displays > Night Shift and try to select the "Sunset to Sunrise" schedule I get the following dialog presented:

Night Shift from sunset to sunrise requires location for time zone to be enabled.You can turn it on in Security & Privacy Preferences.[Cancel] [Privacy Preferences...]

In System Preferences > Security & Privacy > Privacy:

"Enable Location" Services is ticked.

In "System Services" > Details..., "Setting Time Zone" is already ticked.

As a work around I can use the "Custom" schedule, but having fixed times means it won't track sunset/sunrise through the seasons (or I have to manually update it).

Clearly Apple's error message is mistaken or misleading, so what else is required to actually make Sunset to Sunrise work?

I had the exact same issue. The solution I found was to disable/untick all the location services checkboxes, save it, and then enable them again. This seems to reset it and make it work.

I hope that helps someone.