Hi, I have completed all tasks towards Oranos but have not received the portrait. Is this a bug or did I oversee a mechanic that won’t let me receive the portrait? Oranos is my main so I was really eager to get it. 
Have others also have had this problem? Is this the place to contact support for help? Thanks!
If you go into your god selection screen do you have this toggle button?
If it didn’t get unlocked for completing all 16 challenges, it should be unlocked anyway as the community hit 100% at the end of the month.
You may need to wait a few minutes at the main menu for everything to sync. But if not, then maybe you can open a ticket: https://support.ageofempires.com/hc/en-us/requests/new
I don’t think support really checks the forums.