I am wondering whether other iPhone users have this problem: we set the APN settings per Ting instructions, and the settings regularly get lost i.e. it reverts back to default. By regularly, I mean every month or so. This is a tedious issue, especially because the iPhone user is not capable of re-entering the settings herself (not me, a relative).
This has been a problem on the iPhone 4, and the iPhone 5. It has been a problem on the TING CDMA-Sprint network, and the TING GSM-Tmo network. I have not been able to discover what causes it.
The person does not have wifi, so I doubt that causes the problem. Because she has no wifi, she also does not run updates in herself, so running updates in are not the "proximate cause" of the problem. (I noted with interest William Reed's post about updates causing the settings to get wiped out, here: https://help.ting.com/hc/en-us/community/posts/115005997047-Apple-System-Updates-on-i5c )
Does anyone else out there have any experience with this, or suggestions?