Strange problem with outgoing calls

I have a strange issue that I have not been able to resolve. I am running FreePBX Asterisk version 11.4.0 with all the latest updates. When trying to make any outgoing call with the 2 digits “86” in that order, the call immediately dials as soon as the 6 is dialed. This will happen no matter where in the dial string the 86 is.

So if I try to dial:
918665551212, it will only dial 91866
912025558600, it will only dial 9120255586

Any other calls work fine.

I am using Cisco 7970 phones with the SIP70.9-3-1SR2-1S load. All of our internal extensions are 1xxx and 2xxx.

The outgoing route plan is very simple, it only has these entries:
91XXXXXXXXXX
9XXXXXXX

Any help would definitely be appreciated. Thanks!

What about the dial plan in the phone? How did you provision it? dialplan.xml is the filename it pulls.