iPhone 6 - Phone call keypad not recognized Recently, when I am on a call that requires pressing a number on the keypad (for instance: to select an option or join a WebEx), I can press the appropriate button and I see the press respond and hear the tone, but the other end of the line does not recognize that the number was pressed.

I thought it was only WebEx, but two other calls did the same thing today (one of them being an Apple support call).

How can I fix/debug this?

I tried searching Google for "iPhone 6 numeric keypad not working" but came up empty. Is there another term I should use in my search?
As an update, I have not had this happen since upgrading my phone to iOS 10, so I can only assume that it was a bug with previous versions of the operating system.

Aside from that, I have not found a "solution".