What's the delay in receiving information from Samsung a7?

Samsung a7 lags behind in receiving information. Suggestion:

1. If you try to change other geographical locations, the signal strength may be weak.

2. Take out the SIM card and insert it again; Or try to change another SIM card.

3. Try again after upgrading your phone.

4. If it is invalid, please back up the information (contacts, text messages, pictures, etc.). ) and restore the factory settings.

If the problem still exists, it is recommended to take the purchase invoice, maintenance card and machine to the local Samsung service center for testing by professional engineers.