when open messages cant see all message history

have a lot of messages from the past 5 years and im using iphone for the work so the message history helps to see the history of previous comunications, so, it happens not all the time but often when I opening the message application and some message I can see only few last messages but not all of them. usually when I restart an iphone I can see already all messages. Thats happens quite often. Any way to sort this?