iPhone 6 "No service"
Recently my iPhone will often goes into "No service". I have AT&T and sometime it will go outside cellular coverage and the iPhone will never search and camp on cellular service again. I have to turn airplane mode on and then off for it to camp on a cell again. This was not the behavior before. My iPhone used to automatically search and camp on again after it lost and re-enter cellular coverage.
I have iOS 10 but I notice this behavior for a few weeks even before iOS 10 upgrade.