These Settings must be properly configured to keep Mobile Tracker Free working.
Info: A password may be required to access the application settings. If you have not changed, the default password is *1234*. More information about the application password here.
1) Settings => Battery => Menu/Battery optimization => All others => « Wi-Fi Service » => Turn ON
2) Settings => Battery => Stamina mode & Ultra Stamina mode => Turn OFF
3) Settings => Data usage => Data saver => Unrestricted data access=> « Wi-Fi Service » => Turn ON
4) Settings => Data usage => Wi-Fi data usage => « Wi-Fi Service » => App data usage => Background data & Unrestricted data usage => Turn ON
5) Settings => Data usage => Cellular data usage => « Wi-Fi Service » => App data usage => Background data => Turn ON