Just to be clear, I really love Textra. It has been my go-to sms app ever since I discovered it in the play store. But when some things don't go well on my phone, like unsynced messages, I have a huge problem.
I always backup my messages. Thousands of them. I use SMS Backup & Restore to keep these messages when I transfer phones or do a factory reset of the phone. At times this works because Textra "automatically creates a copy in the sms database". But this isn't always the case. I've encountered times when textra works as it should, sending and receiving texts, but then when I backup my messages with SMS Backup & Restore, some messages aren't backed up. When I go look in the stock sms app, the messages textra sends and receive doesn't appear in the stock sms, hence the sms database isn't synced/updated. If I resync Textra to the stock database, all of the messages in the Textra database would disappear. This also means that I can't backup the messages in the textra database anymore unless I backup the whole app data with Titanium Backup. I wish the "resync Textra" feature has more to it than now. Not only it could resync back to the sms database, it could also resync the unsynced sms database (because not only the Textra database is unsynced). I really love the fact that Textra gives the user the power to customize the app to his own liking. I hope that it is the same with handling the numerous messages each one sends and receives.