I know it's what you wrote, but just to be sure, you are *not* copying any users from the template course? And then you are adding a professor-level user with that same form for creating a new course?
In WW 2.19, line 411 of lib/WeBWorK/Utils/CourseManagement.pm should be assigning all of the copied sets to the one new user.
Admin users from the admin course also get placed into the new course. But the copied sets are not assigned to them. Does this have something to do with what you are seeing?
In general, I am not copying any users.
The result is the same without simple configuration files, with only
1. templates and html folders
2. assignments/sets
Both model courses were copied over from v 2.17 and they were upgraded.
What works at least is that once I import the sets into the newly created course, I can use it as template with set assignments.
Automatically assigning sets to new instructors is a fantastic feature for me, by the way.