Minimally reproducible example:
An IAX2 call to this system (with context = from-tieline) to extension, say, listen6, will work in this scenario:
[from-tieline]
exten => _listen[1-6],1,Hangup
include => local
[local]
...and fail in this one:
[from-tieline]
include => local
[local]
exten => _listen[1-6],1,Hangup
And no, we are not using the new pattern matcher.
You must be