It takes several hours for a mobile phone to receive a text message from someone else. What's the problem?

It does have a certain connection with the network signal. The mobile signal belongs to the cellular system. For example, when the network in your area is busy, if you send messages, the messages will queue up in the network system every few minutes. If it's your turn, I'll give it to you. If it's not your turn, I will continue to wait, so there will be your problem.