I changed my programme and the courses on the studentportal no longer match

Courses that you delete in your SisA selfservice remain linked in the studentportal. ICT removes them from time to time, so not on a regular basis. But at some point they should disappear.

New courses are added in a synchronization process between SisA and the studentportal (during the night between 0:00 and 05:00). So the new courses are available the next morning.

If you are still unable to consult the course, the instructor has probably blocked the content for maintenance. In that case it is just temporary.