I don't know what I am doing wrong!, I used to have a freeware MMMX but it was deleted, I even have deleted Mexico from X-plane 11 and reloaded back again, I have deleted all freeware Mexican airports, well just the MMUN payware is there, I don't know what else to do...
I could only suggest you to update MMMX
In spite this issue your MMMX is great!!!