Hi Gregory!
Looks like you are back to using PJSIP only, am I wrong?
Using Chan_SIP was an interesting idea, maybe you are encountering a PJSIP compatibility issue…
If you are back to using PJSIP though can we please retry
Do a pjsip set history clear before (apparently this log is persistent, we don’t want the old entries…). Post the list it shows you here. Search for entries such as the 404 and 486 you had before and do a pjsip show history entry x (where x it the line number on which those are).
Hopefully these will contain the reason of the DECLINED…
Good luck and have a nice day!
Nick