I published a teaching assignment, but have now made some changes to the project. Do I need to republish it?

Yes, you'll need to re-publish a project again if you make changes after you publish an assignment. This will generate a new URL for the new assignment. This is designed to stop e.g. last week's assignment being accidentally changed after it was published, and different students ending up with different versions. By generating a new URL for the updated version, it's easy to check whether a student has used the right one to start their assignment.