Cell phone doesn't accept incoming calls.
I have an ATT cell phone (Samsung S21 Ultra) and until recently an ATT land line. I had the land line ported to a 2nd cell phone (U318AA from ATT). From that second cell phone, I can call the original phone without issue. However, from the original cell phone, I get a message that says, "Your call cannot be completed as dialed . . . Message 2 US01LV". Sometimes it says Message 1. I can check voice mail on both phones. Text messages work both directions. Internet connections work on both.
I haven't gotten a single incoming call on the new cell phone since it was set up. I checked the settings to make sure I wasn't blocking incoming calls somehow. Nothing seemed out of line there.
It's a very effective way to stop junk calls, but what's the point of having a phone if no one can call you?