Samsung S20 FE.
I needed to backup then modify/standardise then restore SMS messages when I changed to the S20 FE.
Now, a new SMS message from a contact for whom there is already a thread / conversation starts a new thread. The name plus the contact's phone number appear at the top of the new thread display. For the old thread just their name (as in Contacts) displays.
Annoying that a new thread is started when there is already a thread for that contact.
What can I do to ensure all messages for a contact are in the same thread?
Also, just noticed (!?) that I can't send a message using a pre-conversion thread / conversation. The Messages app forces me to start a new thread / conversation. Very annoying.
I wonder whether the backup/restore process, and particularly editing the backup CSV file in Excel, changed the data so that tests in the Messages app didn't return matches for thread ID or address.
Any tips welcome.