This question is precisely the opposite of the existing question: "How can I send SMS messages from my Google Voice number without using the Voice app?"
Since installing the Google Voice app, text messages that I send from the ordinary Messaging app are coming from my Google Voice number. I don't know how or why - no setting I can find in the messages app mentions GV or my GV number.
- I currently use my OnePlus One's built-in Messaging app for SMS. I installed Hangouts and Google Voice, but both are NOT configured for SMS. (I use Google Voice occasionally, but I still use my real cell number directly for most calls and texts to my friends.)
- In the "Messaging" app settings, it says "SMS Enabled."
- In the "Hangouts" app settings, it says "SMS Disabled."
- In the "Google Voice" SMS view, it says, "You are now receiving SMS in Hangouts." This is obviously not true, but doesn't seem relevant to my problem either. (I'm guessing that the writers of that particular message couldn't conceive of any SMS app other than GV or Hangouts. :)
- When I actually receive messages, I get them in the "Messaging" app as expected. When I reply to those messages, which were sent to my AT&T number, my replies come from my GV number, confusing my friends.