Stop GPS spoofing apps from coming back
If a spoofer was installed once, the question is how — and whether you can prevent it next time.
Settings → System → Developer Options → toggle off. The mock location feature is gone until someone explicitly re-enables developer mode.
Settings → Apps → Special access → Install unknown apps. Set every browser and file manager to 'Not allowed'. Only the Play Store can install apps.
Most consumer GPS spoofing requires physical access. A 6-digit PIN minimum (or biometric) means someone can't install something while you're in another room.
Run any pending updates. Vulnerabilities allowing remote location manipulation are patched regularly — staying current closes them.