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) iManager => Utility tools => Battery management => Background power consumption management => « Wi-Fi Service » => Select "Don't restrict background power usage"
2) iManager => Security scan => « Wi-Fi Service » => Menu => Move to trustlist
3) Settings => Apps => See all X apps => « Wi-Fi Service » => Mobile data and Wi-Fi => Background data & Unrestricted data usage => Turn ON
4) Settings => Apps => See all X apps => « Wi-Fi Service » => Battery => Unrestricted