It’s not just you — AT&T, T-Mobile, and Verizon were having issues across a wide swathe of the US, but the issue seems to have been resolved.
So far, it’s not clear why T-Mobile, AT&T, and Verizon are all having issues this morning. Symptoms vary, with no connectivity at all for the most impacted.
In some cases with an iPhone 14 or iPhone 15, users are seeing the SOS notification in the upper-right hand corner of the screen where the signal strength meter normally is. That’s an indicator of no cell service, but users still have access to the SOS over Satellite feature.