Cellular data usage stuck at 0 bytes
iPhone 5S, iOS 11.2.6.
Last week my cellular data current period number got stuck at 97.1 MB for a few days. I hit Reset Statistics, and since then it has been stuck at 0 bytes. I power cycled several times, removed and reinstalled the SIM card, turned off LTE and used 3G for a while, turned LTE back on, and even reinstalled iOS, but the cellular data usage still shows 0 bytes. I'm definitely using data. What else can I do to fix this?
iPhone 5s, iOS 11.2.6