Delayed messages

Just a quick one... has anyone had any experience where someone's DM has come through late, or even the next day and the timestamp is of when they sent it?

Like, is this a technical glitch or?

So as an example....

You can check a chat thread with someone and their last message will have been from yesterday. When youre checking its say, 9pm. You check in a few hours and it'll show a new message from 6pm which wasnt there before?