These Settings must be properly configured to keep Cell Tracker app working.
1) iManager => Apps => See all apps => « GPS » => Mobile data & Wi-Fi => Background data & Unrestricted data usage => Turn ON
2) iManager => Apps => Special app access => AutoStart => GPS => Turn ON
3) iManager => Apps => Special app access => Background power consumption management => GPS => Turn ON
4) iManager => Security scan => Settings => Regular scan reminder => Turn OFF