After days of trying to recover missing text messages, trying every solution mentioned on numerous websites and using two different phone recovery apps, nothing worked. Then in desperation I did this, and it worked:
I deleted all optional apps that I had downloaded over time, leaving only a few built-in Apple apps that I couldn't delete. I was trying to make my phone as "clean and simple" as possible.
Then I followed these directions: iCloud Backup Restoring
- Reset your iPhone. Go to Settings > General > Reset > Erase All Content and Settings.
- Set up your iPhone. Follow the onscreen setup steps until you reach the Apps & Data screen, then tap Restore from iCloud Backup > Sign in to iCloud with your Apple ID > Choose the backup you want.
- Wait for the process to complete. Stay connected and wait for a progress bar to appear and complete. Depending on the size of the backup and the network speed, the progress bar might need a few minutes to an hour to complete. If you disconnect from Wi-Fi too soon, the progress will pause until you reconnect.
The italic text above was the key for me, I think. After erasing all content and settings, I saw 2 options for a backup: my current phone, and a previous phone. Fortunately, I had changed phones only recently, so my previous phone contained the texts that I really wanted to recover.
I backed up from my previous phone. After a couple of hours, I saw that there were some changes; for example, some old apps that had been on my previous phone reappeared. But alas, the text messages had not reappeared. I figured they were completely gone now.
But this morning, after the phone was left undisturbed overnight, the old, missing text messages were back!
It seems like a miracle. There was a thread from my son that was crucial to me. It was lost, and now I have it back.
I hope you can find an earlier backup that still contains the messages you really want.
P.S. I now have my phone backed up on my computer, so I think the text messages can be recovered more easily in the future, if need be.
Good luck, and may Apple rot for deleting our texts.