There can be several unknown reasons which can make your call history disappear from your Android device. It might happen that the existing call logs are getting replaced by the new ones or someone else is deleting the call history from your Android phone intentionally or unintentionally. Oftentimes, there are some other unexpected reasons which are responsible for the deletion of your Android call history.
Accidently or mistakenly deletion
Virus or malware infection
Failure of system update
Due to human faults.