Why you may have issues sending SMS texts via Apple Watch Series 3 cellular

Scott Stein, on sending SMS texts via his cellular Apple Watch:

I have experienced some quirks, particularly with text messages, and investigating them revealed some limitations in how the Apple Watch handles its wireless interactions.

And:

The Apple Watch really, really wants your phone to be powered on somewhere, connected to Wi-Fi or LTE. That location doesn’t have to be anywhere near the Watch, however. Your iPhone can be sitting on your nightstand at home, and you could be 50 miles away — though, obviously, someplace that still has cellular coverage.

The different scenarios are subtle. Scott does a nice job of laying out the rules. And here’s an Apple support page that addresses these issues, though I think Scott’s writeup better addresses the scenarios involving SMS.