iPhone location defaults to another city

Try turning Location Services off, wait 30 seconds or so, then turn it back on and see if that corrects the problem. If that doesn't help, try Settings > General > Transfer or Reset Phone, tap Reset, then tap Reset Location & Privacy. You'll need to re-grant permission to all the apps you want to have able to access your location.

Hope this helps.

Regards.

Is WiFi turned on (if not connected to a network) when you experience this problem? or have you turned WiFi off entirely? Are you indoors or outdoors where GPS might be able to determine a location? Are you in a building where some kind of cellular booster is installed (some office buildings have these to provide indoor coverage where the towers can't provide good service).

Who is your cellular provider?

If the device is unable to determine a location based on nearby WiFi networks, cell tower triangulation, or GPS, the location will be based on the IP address of the egress point from whatever network you're on to the Internet which may be many miles away from your actual location.

If you're using iCloud private relay, make sure you have checked "Maintain general location in the IP address location settings.

If you are using a VPN, disable it, or better yet, remove it entirely if it’s not required by your employer or school to access their systems.

Turn Location Services and GPS on or off on your iPhone, iPad, or iPod touch - Apple Support

I don't know if the browser based services are only getting your location based on your ISP. A possible reason for an incorrect location is explained in the section titled, "The first time that you sign in with your Apple ID on a new device" by clicking on the link for the support article 'Two-factor authentication for Apple ID' --> Two-factor authentication for Apple Account - Apple Support and in Reject unknown sign-in attempts - Apple Support

"The notification might include a map of the approximate location of the sign-in attempt. This location is based on the new device's IP address and might reflect the network that it's connected to, rather than the exact physical location."

If you're connecting with wifi and not cellular, and the Internet service provider has their headquarters in another location, it may report the service provider's location and not where you are located. If you're using a VPN the location could be the VPN server's location.

Have you checked Location Services to make sure that those apps are allowed to use that function?