Issue with ‘Find My Friends’ - dad’s location not showing on iPhone or iPad but works fine on my MacBook

You may try some of these steps, please check after each step...

1. Sometimes, a simple restart can resolve temporary software glitches. Turn off your iPhone, wait for a few seconds, and then turn it back on.
   1. Restart the device. That's it.
   2. Still not solved --> Force restart iPhone - Apple Support
2. Reset Network Settings: Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings: Only network settings are removed.
   1. When you reset network settings, previously used networks and VPN settings that weren’t installed by a configuration profile or mobile device management (MDM) are removed. Wi-Fi is turned off and then back on, disconnecting you from any network you’re on. The Wi-Fi and Ask to Join Networks settings remain turned on.
   2. To remove VPN settings installed by a configuration profile, go to Settings > General > Profiles & Device Management, select the configuration profile, then tap Remove Profile. This also removes other settings and accounts provided by the profile. See Install or remove configuration profiles on iPhone in this guide.
   3. To remove network settings installed by MDM, go to Settings > General > Profiles & Device Management, select the management, then tap Remove Management. This also removes other settings and certificates provided by MDM. See “Mobile device management (MDM)” in the iOS Deployment Reference.
   4. Reset your Network Settings. Tap Settings > General > Reset > Reset Network Settings. This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before.
   5. 
3. If the issue persists, you can try resetting all settings on your iPhone. This will not erase your data but will reset all personalized settings to their default values. Go to Settings > General > Transfer & Reset > Reset > Reset All Settings and confirm the action. Note that you will need to reconfigure your settings afterward. All settings—including network settings, the keyboard dictionary, the Home screen layout, location settings, privacy settings, and Apple Pay cards—are removed or reset to their defaults. No data or media are deleted.
   1. Reset All Settings: Return iPhone settings to their defaults - Apple Support:- Return iPhone settings to their defaults
   2. You can return settings to their defaults without erasing your content.
   3. If you want to save your settings, back up your iPhone before returning them to their defaults. For example, if you’re trying to solve a problem but returning settings to their defaults doesn’t help, you might want to restore your previous settings from a backup.
   4. 
4. Make sure you have the latest updates installed.
   1. Update Over-the-Air (OTA) —> Update your iPhone or iPad - Apple Support (IN)
   2. Update using iTunes/Finder —> Update your iPhone, iPad, or iPod touch - Apple Support (IN)

If none of the above steps resolve the issue, it is recommended to reach out to Apple Support or visit an authorized service center for further assistance. They can provide specific guidance based on your device model and iOS version.

There are two scenarios: People and Devices under Find My

In the Find My app, there are distinct functionalities for tracking People and Devices. Under the People tab, the sharing of location is limited to a single device. If multiple individuals are using the same Apple ID, only one person's device location can be viewed at a time. This means that if you've shared your location with someone using the Find My app and they are also using the same Apple ID, you'll only be able to see the location of one of their devices under the People section.

Conversely, the Devices tab offers broader visibility. Irrespective of whether multiple devices are linked to the same Apple ID, all these devices' locations can be shared and viewed. This tab allows for comprehensive tracking and visibility of all devices associated with the Apple ID, enabling users to locate and monitor the whereabouts of various devices simultaneously.

Essentially, the distinction lies in the limitation of sharing a single person's device location under the People tab versus the broader accessibility to view all device locations under the Devices tab, regardless of the number of devices linked to the Apple ID.

Summary

1. Multiple Devices with the same Apple ID...
   1. The People Tab will show only one device
   2. The Device Tab will show all the devices
2. Multiple Devices with multiple Apple IDs...
   1. The People tab will show all the devices except your own which is shown under the Me Tab
   2. The Device Tab will show all the devices (If they are part of your family)

The pic below is self-explanatory