Cool!! I'm happy to hear that it's working for you, too. So that seems to be the winning combination for Sailfish on T-Mobile USA: the APN settings above with IPv6 for the MMS protocol. This is just great! It's interesting that that bug you found only manifests when connected to their other APNs. It must be some weird compatibility issue, though I suppose it doesn't matter now. BTW, I've found that these same APN settings will still work if you are connected to 2G (prefer 2G setting in Settings or with 2G only in US Aqua Fish). Where I live, I only have a weak 2G signal and good 4G -- strangely, there is no 3G available, so not sure about that band. Hurray for Sailfish on T-Mobile USA. Enjoy your device!