Old Messages Not Loading

I really need my older conversations with someone who I still text but after July 2017, his messages do not load. My messages go back to when we first began talking in April 2017 but his do not so it is only blue messages. On my MacBook air on iMessage, neither of our messages load past September.

I have an iPhone 7 Plus and have reset the settings of my phone and done multiple soft restarts. I know for sure they are not deleted. Does anyone know how I am able to get our full conversations to load?

Thank you!