The Schedule Maker floating toolbar locks down the filters (school year, group type, term) so when you go to other schedule maker related tasks, they cannot be changed. This is strictly an onRecord/Schedule Manager task.
For some reason, there are some onRecord tasks that continue to be locked down, even after navigating off the Schedule Maker page. There are some other onRecord tasks, such as Section Attendance, where it does unlock the toolbar and when you navigate back to onRecord > Settings > Schedule Sets, the filters are once again available.
You can also switch to a different persona/role and switch back and that will drop the floating toolbar which will allow you to change to another Schedule Set/Group Type.