I have been sending iMessages (blue) to contacts and texts (green) to contacts, while being connected to both LTE and Wi-Fi networks, and I have sent my messages and they have been delivered. However, when I click on the contacts I have sent texts to, I cannot see some of my messages in the conversation (have never deleted messages in my conversations) that I definitely sent (the following messages in the conversation are intact). In the case of some of my iMessage contacts, I can only see the messages I have sent and see only for two seconds in the messages main menu that the contacts have responded, but there have been no notifications nor actual messages being displayed in the conversation's screen. I have the Verizon 19.1 carrier update, along with iOS 8.3.