I have an iPhone 6s with iOS12. I have received a pop-up notice that new carrier settings are available...I select the option to update them now. I select update and the carrier settings don't update and the pop up comes back again. I have connected my iPhone to iTunes to do the update and select check for updates. The pop up box for new carrier update setting shows as available and then once I select update, I get a pop up from iTunes that my carrier updates was successful, but then the box for new updates pops up again after I disconnect from iTunes. I have tried to a Reset Network Settings and this does not work as a successful solution. The other option I suggested by my local Sprint store sales rep is to Erase All Content and Settings, which I believe happens when the battery is pulled out as I am planning to take advantage of the $29 battery replacement that Apple is offering. (I don't know if this is any issue with the iPhone 8s and iOS 12). My other option may be to upgrade if a full erase and reset and a reinstall of iOS 12 doesn't work. Please help with any suggestions. Thank you.