This is an old story, started from the beginnings of the Brax3 phone. Myself and my wife both have the brax3 phones,had them for a year now. We tried everything to fix the SMS/MMS problems with the included messaging app. We even tried a few other apps, most did not work, until I discovered the Chomp messaging app on APKPure. That app ticks all the boxes and it makes my wife happy,(happy wife,happy life). Not sure about the security and privacy aspect of the Chomp app, but it works, and it can be customized to your liking. Try it, it may help you like the Brax3 phone and help ditch the Samsung.