Sonoma 14.2.1 Messaging locks up and doesn't sync

For the past 6 weeks we have been wrestling with this issue. One person on our messaging chain married and changed her name. Ever since then we go through periods where messaging locks up and must be forced quit. But when you re-open it simply locks up again. All of our devices are up to date in regards to IOS and deleting the previous conversation thread sometimes temporarily solves the problem. But then inevitably it reappears and often at the most inopportune time. Please spare us the cut & paste stuff about how to force quit an application or ensuring our software is up to date. And rebooting does nothing to help. We reboot our devices regularly, even daily recently. We know how to force quit the application. What we would like to know is how to permanently fix the Apple application that comes built-in to our devices. This is not a 3rd party application. It is Apple messaging.