I also had this problem, thankfully it has an easy solution. Not only does the instructor need to be affiliated, but the course must also be affiliated. If the course was made before you were affiliated the course will have the old non affiliated Institution name. To fix it simply edit the course information, and change the institution field to the 'actual' affiliated institution name, the one with the icon next to it.
That did the trick for me, hope it helps you too.