Make change to a thing but it is not accessaple

I have a popup, In it I’m showing students details and selecting more than one student (saved in custom session) ,
using backend workflow for each selected Student I do create a new thing (called course_students) that contains status + student thing,
my next step is to add each new object to a list at courses thing ( it has a list of course_students)

the problem is that I do not see courses thing in the list when I try to make changes to thing at my workflow, while the course thing (and all others ) appears to create new things!!
any idea about how can I solve this issue ?? please
FYI , I am saving the course unique ID as a parameter in the URL.