Text message/Lock screen fail?

[WildDevon]

So sometimes I'm texting someone with my phone, I expect to receive a message regardless of the phones screen being off right? Apparently my phone doesn't seem to think so because sometimes when my phone's screen is off it won't receive a message unless I turn on my phone manually. When I turn on the phone, THEN it receives the message. The time on the message is even when the text was received, but I don't get a notification unless I turn my phone on, Anyone else experience this? It happens SOMETIMES, not all the time.