I have a 5s on 8.1.4 and every time I get e message, it is delayed, the time stamp shows the right hour i got the message but it is displayed in the messages app minutes later. It happens when i text my gf with android and now it happens with other people who have iphones. Here is an example, a conversation between me and someone with an iphone 5s with ios 9.1 . In the second photo, the message received at 9:16 was actually displayed on my phone in the messages app at 9:54. iMessage already has "send as sms" enabled. Here is the first photo where the timestamps are messed up.