Merging text threads with new contact information.

My friend and I text often, today a random number texted me and said it was his new number. Is there a way to combine or merge the 2 text threads? As in- any texts I send to the new phone number are in the same thread as the old phone number. It would be nice to have our entire conversation together and all of the pictures, links, and GIF’s we’ve sent each other.

I saw something in the edit feature that said (sorry I don’t remember!) something like link with contact. I did that and now the 2 text threads are still both separate but have the same contact name and photo. When I click on “info” on both contacts, they both have the 2 phone numbers listed. Is there a way to combine these threads? I’m on iPhone 14 Pro Max and this happened right before I updated to iOS 17.3.1- just now I updated to iOS 17.3.1 and it’s the same issue. I’m attaching a screenshot of my “Messages” app where you can see 2 different text threads with the same contact photo; I blacked out his name but they’re the same. Also, you’ll see that the 2 text threads have the same time stamp. The top thread is his new number and the bottom thread is his old number. The last time we texted was Thursday so they shouldn’t be right next to each other and with the same time stamp.

Any help or insight is greatly appreciated!