How can I get Cellular Network State to be "connected" on Moto X 2nd Gen when on roam?

[AC Question]

My new Moto X 2nd Gen has severe delay sending & receiving even simple texts when on roam....Yet calls work fine. I noticed that the only difference between it and my wife's Moto X 1st Gen (as far as settings etc) was that hers shows "connected" all the time, whether on roam or not, and mine always says "disconnected". My roam data is on...cell data is on etc... It appears to be a problem caused by the new Lollipo 5.1 running it (as 3 other phones in our home work fine from same tower when on roam (as far as sending short texts when on roam). Does anyone have a solution? That is, how can I get it to be "connected"? I've done all the typical PRL and Profile Updates....Even Factory Reset etc.... My carrier is "working on it" but....nothing they've suggested works. They're trying to say the roaming tower just doesn't work for some phones...But that doesn't make sense when all the other other Motorola phones in house work fine on it. And I even had my phone number briefly associated with one of the other phones and it worked fine. In my opinion it is definitely an issue with the Moto X 2nd Gen. (or software/apps on it). Any suggestions?