Why do I receive old messages anytime I turn on my phone?

[Petromina Naeze]

Anytime my phone restarts, I frequently receive read messages from mobile network and banks,configuration messages too. Even after deleting them,they will still appear as unread next time. It wasn't like that, it developed it on it's own . I use TECNO M6. Thanks I await your reply

 

[srs27a]

What type of messages are you getting? Notification or text?