iMessage not working properly with only one contact on iPhone.

Hello, I recently came across this issue where iMessage has been super glitchy, but only with one contact. Whenever I search up an old message with them and click it, it doesn't want to take me there. Also, if I try to scroll to old messages with them, it takes me back to the same messages from October and not the actual old messages. This happens every time, and I'm pretty sure these problems started happening when I got my Macbook. I synced my messages I believe because it was the only way to get the messages to my mac, but now my icloud is full and I feel like thats not letting my go back to those messages, even though it works with literally everyone in my contacts but them. They also show up as "Maybe: their name," and it's just really odd and I feel like I messed something up while trying to set up my Macbook.

Also, everything I said above only applies to my phone, not my mac. If I try to do all of this on my Mac, the messages will appear and I am able to scroll without a problem.

I don't want to keep clicking random buttons and end up deleting all my data, but all I want is for this glitch to stop.

**I am up to date on ios**