iMessage won’t load old texts on iOS 11.2

Hello.

I have an iPhone 8 +, iOS 11.2, and I have it for a two months. I started a new coversasion this month on iMessage and it won’t load the old messages we had this month.

The first time I read that you just reset the settings and it worked for me for one time. But it happened again not loading old messages. I tried to reset again and it didn’t helped.

Also it’s not loading old iMessages only in this conversation. But in others it’s loading.

How I can fix that?

Thanks!!