The weather/astronomy wallpaper used to show my current location Southeastern USA.

My location settings are on and iPhone is up to date. I’ve tried turning phone off and on again but still no green location dot on the map. It certainly used to be there. iPhone 13.

You cou try to reset your location services :

If you would like to reset all of your Location Services settings to the factory default, go to Settings > General > Transfer or Reset [device], tap Reset, then tap Reset Location & Privacy. When your location and privacy settings are reset, apps will stop using your location until you grant them permission.

Source: About privacy and Location Services in iOS, iPadOS, and watchOS - Apple Support.

On your iPhone, go to Settings > Privacy and Security > Location Service and make sure "Astronomy" is activated.

You are most welcome!