We have a main SIP trunk, that goes through to an IVR. The calls come through fine, and people can choose options.
We also have a number forwarded by our provider to the main number. Those calls also come through fine, but customers cannot choose options from the IVR.
Is there anything about the trunk settings I should look at that might mean this only works with our main phone number?
There’s a setting in inbound routes - Signal Ringing - that possibly might be appropriate;
Some devices or providers require RINGING to be sent before ANSWER. You'll notice this happening if you can send calls directly to a phone, but if you send it to an IVR, it won't connect the call.
Yes, the IVR answers calls in both cases, but DTMF is not recognised on the forwarded calls, or for some other reason button presses don’t work. This makes me think it might be something about the caller ID of the trunk, but I’m guessing.