After a bit of research I see that Aastra/Mitel phones have an issue with blind transfer when using PJSip. Something about Aastra/Mitel missing a response back from the server saying the call was complete/Transferred away.
I found a patch that Asterisk released to assist with the issue. I also found where FreePBX is putting the fix but it seems to be only available for FreePBX 15. At this time FreePBX is still in beta and I am not ready to push that out to a production system (Assuming it is not recommend ether)
Can anyone point me where I can add the few lines of code to my current system to use this fix from Asterisk?
Asterisk Bug Ticket: https://issues.asterisk.org/jira/browse/ASTERISK-26333
FreePBX Issue Tracker: https://issues.freepbx.org/browse/FREEPBX-15011