I have had issues with the Message+ app not notifying me. I opened the app this morning to text someone, and had tons of messages from over 12 hours prior that I never got notified for.
This was an issue on my previous phone as well, but I just chalked it up it being an older phone. I now have a Galaxy S22+. This happens frequently, and I've tried all I can. Is this an app issue? Should I just use a different default app? Its really frustrating to not be getting my text messages.