enhanced 4g lte mode - SMS not working


    I am writing this post to document an issue and a solution that may be of use to others who come across it since I was not able to find any useful posts elsewhere that relate.  I have two new factory-unlocked Moto G4 Plus phones that I purchased from a 3rd party and brought to T-Mobile to replace aging Galaxy S4 devices.  A major reason for upgrading was gaining access to Band 12 and voice over LTE (VOLTE) coverage, which T-Mobile has been expanding.


    The default setting under Settings:more:cellular networks:Enhanced 4G LTE Mode is "enabled," which allows the phone to use VOLTE.  Coverage with this setting enabled was exceptional, with no dropped calls vs. my S4, which repeatedly dropped calls in certain areas. However, with the Enhanced setting enabled, SMS was mostly non-functional.  Even though messages would say that they had sent, they would not be delivered to the recipient, and incoming messages wouldn't show up on the phone (even though they would arrive in my account, as verified by a DIGITS duplicated device with the same phone number).  The SMS issue could be isolated to the Enhanced switch...enabled-SMS woudn't work, disabled-SMS worked fine.


    The problem with disabling "enhanced 4G LTE mode" to make texting work properly was that it put me back to living with dropped calls.


    Moto support was unable to identify the issue and wanted to factory reset the phone.  However, before doing that, I contacted T-Mobile support a second time and worked with a technician who was eventually able to identify the cause, which was easily resolved.  The cause turned out to be re-use of a dated sim card in the new phone.  Although it generally worked, the sim card apparently did not fully support current Band 12/VOLTE features.  By installing a new sim card, the issue was resolved, and texting now works using Enhanced 4G LTE mode.


    Hope this information helps someone struggling with the same problem.


    *Discussion moved from Other Android Discussions to Not Sold by T-Mobile Discussions - Marissa

      All replies

      • ericksonline

        Re: enhanced 4g lte mode - SMS not working

        Hello! Thank you for this post! I've spent countless hours the past couple days trying to troubleshoot this issue. I got two Moto G4's for my wife and I, and three Moto G4 Play's for my kids. All three G4 Plays work flawlessly. The two G4's can't receive SMS messages while on Enhanced LTE. Everything else works fine. T-Mobile has been much more willing to help than I expected, but we haven't found a solution yet. Motorola just gave me the runaround and told me to return the phones! I'll be heading to a T-Mobile store today to get a couple new SIM cards to see if that makes a difference. Thanks again for sharing!

        • ericksonline

          Re: enhanced 4g lte mode - SMS not working

          After some further troubleshooting, this does not appear to be my problem. I tried swapping a new SIM card to my device, but it didn't make a difference.

          • jm00700

            Re: enhanced 4g lte mode - SMS not working

            As a follow-up, SMS stopped functioning again when Band 12/VOLTE is activated.  No additional apps had been added to either phone between working/stopped working, so it's unclear why it stopped functioning, other than possibly having something to do with rebooting the phones at some point between working/stopped working.  I'm now back to having Band 12/VOLTE disabled so that SMS will work reliably and will try to follow up again with support to see if there are other possible solutions.  Bearing in mind that I have two G4+ phones that are used by two different users and have very few apps in common, I'm inclined to think that this is an issue with the Moto device/software.  Will probably factory reset one of the devices to see if the issue corrects.

            • magenta1917000

              Re: enhanced 4g lte mode - SMS not working

              Same issue here with two unlocked Moto G4 Plus. Service worked flawlessly since December, then one day in early June I stopped receiving text messages. I couldn't even text myself and receive it. A few days later it started happening on my wife's phone. T-Mobile support could not find anything. Factory reset didn't help. I went to the TMobile store, they put my SIM in another phone and it worked fine, so they blamed the device. After doing some Googling, I tried disabling the Enhanced LTE Mode and everything started working.