Again I assume you have HTTPS (I would never use HTTP for this purpose) enabled under System - Network - Interface and therefore you see wan1 with Access HTTPS (also HTTPS on Interface internal I assume)
Secondly you have under System - Admin a user with Trusted hosts 0.0.0.0/0 (as you wrote). You are using the same user to connect to the internal interface to administrate your FortiGate 60 - correct? Then you never tried something with IP/MAC binding? If so that' s fine.
If all the above is true, then it should be possible to connect from a computer attached to the internal interface to the FortiGate 60 using https://200.67.122.229/ in a browser. If this is not working, then I have no idea what could be wrong.
Currently I' m using MR5 and not like you MR6, but probably today I will upgrade a FortiGate 60. I hope your problem is not related with MR6, otherwise I will know this soon!