Short Answer 
To resolve issues with seeing someone’s location on an iPhone, ensure their Location Services are enabled, confirm both devices have stable internet connectivity, and verify that location sharing settings are correctly configured and both iPhones are updated to the latest iOS version.
Step 1: Check Location Services
One of the primary reasons for not seeing someone’s location on an iPhone could be that their Location Services are turned off. Ask the person to navigate to their iPhone’s Settings and ensure that Location Services are enabled. This is found under Privacy & Security, and it must be toggled on for their location to be shared accurately.
Step 2: Verify Network Connectivity
Both you and the person sharing their location must have a stable internet connection for the location data to be transmitted correctly. Without a strong network, the location may not update or display. Check the following:
- Ensure Wi-Fi or cellular data is turned on.
- Look for any network issues or downtime that might affect connectivity.
- Restart the devices to enhance network performance.
Step 3: Review Sharing Settings and Software Updates
Confirm that the person has specifically shared their location with you through the Find My Friends or Find My app, and check for any privacy restrictions they may have set. Additionally, ensure both iPhones are updated to the latest iOS version to eliminate any bugs affecting location sharing. Updates can resolve many issues related to functionality.