Le me be more precise on my settings on inbound route (item 6 above):
It needs the DID field filled in to work, if you use leave it blank (accept “any DID”) it won’t work ad it goes through a different code sequence (kind of “catch all” settings)
In my case I set a DID in the registration string for the incoming trunk (e.g. user:[email protected]/DID) and used the same DID in the inbound route DID setting.
Just used trial and error approach and this is the conclusion I came to.
Cheers