I haven't sent a short message on my mobile phone for a while.

If the phone automatically clears the information, it is suggested that:

1. Open phone settings-Application Manager-All information-Clear data.

2. Uninstall the downloaded and installed third-party software for observation.

3. Back up data (contacts, text messages, photos, etc. ) and restore factory settings (Settings-Reset/Privacy-Restore Factory Settings).

4. If the phone has an updated version, please try to upgrade the operating system.

If the problem still exists, it is recommended that you take the machine, purchase invoice and warranty card to the local Samsung after-sales service center for testing.