6s - Outgoing Calls Only Ring Once

[Buadhai]

I recently gave my iPhone 6s to my father-in-law. Seems to be working fine except that when you make an outgoing call you only hear one ring no matter how long it takes the other party to answer the phone. If you turn on speaker phone, then you hear every ring.

What have we set up wrong to cause this?

(I never made outgoing calls on the 6s, so the problem may date to when I had the device. Who knows?)

 

[cmaier]

That sounds more like something happening at the network level than an issue with the phone itself. Maybe something to do with the sim or the provisioning.

 

[Buadhai]

We considered that, but if it were a network or carrier problem then:

• Why doesn't it affect other phones on the same network?
• Why does turning speaker phone on restore the outgoing ring?