Generated config files (iax_additional.conf) getting values from elsewhere?

I’m having trouble with my asterisk config files generated by FreePBX. I have 5 IAX trunks set up (both incoming and outgoing) and something somewhere is appending details to the config that I haven’t set in the GUI, but only if they have a certain name. For example, if I make a trunk called TRUNK_TEST, the following appears in my iax_additional.conf:

[OUT_TEST]
host=provider ip address
username=userid
secret=password
type=peer
context=from-trunk-iax2-OUT_TEST

[IN_TEST]
secret=password
type=user
context=from-trunk

(n.b.: I left the peer details as the default).

This is what I would expect to happen. If however I change the names of the incoming/outgoing trunks to ones that I previously had set in my system (e.g. IN_phonenumber) then my parameters in my trunk settings are ignored and replaced with seemingly global values. E.g.:

[IN_01753279927]
secret=[redacted]
type=user
context=from-trunk
requirecalltoken=no

[OUT_01753279927]
host=iax-lb.gradwell.net
username=[redacted]
secret=[redacted]
type=peer

The redacted usernames and passwords above ARE settings I previously used - a password change was enforced and now I am unable to change my passwords for my trunks in the web GUI.

Any ideas what’s overriding this?

Can’t imagine freepbx is doing this. Type the following commands at the CLI to see what is in the IAX config database.

[[email protected] ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3427
Server version: 5.1.61 Source distribution

Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use asterisk;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select * from iax;

Thanks for the post, this got me headed in the right direction. The details going in to my configs were in that IAX table in the ASTERISK database, so a few lines of SQL to update them and my configs are right now. The question is, how did that data get there and why can’t I find it in the FreePBX web interface?