I would have to see the differences between the raw dialplan and how you are declaring the TRANSFER_EXTENSION, can’t really tell you why without looking the dialplan more.
Your entire pastebin is filled with external_replaces because it looks like that how you redacted everything. So really that is calling on whatever extension is being used. If you didn’t redact/replace things with external_replaces then you’re sending the call to external_replaces as the extension at some point.