Tried to follow this, having a heck of a time.
I went into system etc apn xml, found my carrier apn named T-Mobile LTE
But it didn't match the apn in settings under access point names. Also you said to also find the dun, there was no dun for TMobile LTE any where. I seen dun entries for other TMobile apns, but not the one named TMobile LTE. There were manyother TMobile entries, like TMobile US 160, 260, 270 and a bunch of other numbers. Under my settings/access points, the apn selected is named TMobile LTE with no number after, so I figure that's what I need to look for in the xml, so I find it, but again, the info under it doesnt match the MCC and MCN numbers don't match and the Apn type doesn't either. For example , in my settings/access points, the last apn type is xcap, but in the xml xcap isnt there, there's just default, supl. Mentioned it because Im guessing they need to match? But they don't.
Also, when I do find the right one in the apn xml what exactly am I supposed to do?
Delete user_viable=false Ok I understand that, but where exactly is that supposed to be? Under my carrier? If so, I'm using solid file explorer, so I searched the words user_viable= false and thru out the entire XML file there are only 4 instances of user_viable= false and they are all under Verizon apns. So I'm not sure what's up with this, because it's definitely not under the TMobile apns.
And then you said NOT to delete read_only=true? Ok I understand that , but again, is that supposed to be under my carrier right?
So basically, when I find the correct apn in the xml, user_ viable = false should listed, and I'm supposed to delete that, then save and change permissions to 0644 and reboot? Then after reboot go into settings/access points and reset apn.
Is that right? If it is, good
Now I have to figure out how to find the right apn in the apnxml file.
Sorry for all this trouble.