Restore SMS Messages with Titanium Restores then Deletes! I understand I /should have/ used a different app for backing up my messages.

I did not.  I used Titanium, and made full backup of apps and data.

I was apparently also using Android Messenger and not Google Hangouts to store my SMS.  This service was apparently deprecated in August.

I go to Titanium to restore my messages, and for a moment, it looks good!  I see all my messages.  Then they rapidly delete themselves before my very eyes!

I try again, I reload app+data, or data only, and the same thing happens---I see all my messages, then I watch it delete them one by one very quickly.

What is happening in this process, and how can I prevent it?  Where are they going?

About adb backups, not TitaniumBackups, but is this relevant (could I get my SMS back if I have an old ADB lying around?)?
https://www.reddit.com/r/Android/comments/3nrork/adb_backup_and_restore_not_all_its_cracked_up_to/
OK, here's the deal...

So, the issue was that Messenger vs Hangouts is controlled external to your application, and external to your google account manager, it's an OS-level setting.  So, the issue was I had to sign into messenger, agree to terms, declare it my default SMS manager, and then when I did the restore, it didn't automatically delete.  I guess prior to this, messenger and hangouts were in a fight somehow.

This is probably a one-off problem, I had not converted from the deprecated messenger to the supported Hangouts, my phone was kind of grandfathered in, while the default SMS program had changed.  

If you are in this situation in the future, set your default SMS to messenger, and hangouts won't delete your messages.