I just got this phone and can't get any 3rd party apps to send mms pictures. I wanted to use Textra, and tried putting in apn settings I found online for Virgin, but they still won't send, just automatically says failed. It seems to send fine in the stock messaging app. I've tried looking for apn settings in the actual phone but can't find them? Under settings and mobile networks it has Data Enabled, 4G settings (which you can't change anyway?) Network Mode and Connections Optimizer. Seems like this should be a basic function so I'm confused as to why this is a problem? Not rooted, would rather not just for this.