When I open a time slot I want to rearrange the order of the tasks (ideally it should really be sortable, but for now this is what I'm doing.)

When I move a single task to a different place in the list, the time slot window closes. This means if I want to rearrange multiple tasks, I have to move a task (the window closes), reopen the window, move another task (the window closes), reopen the window, etc.

The window should stay open even after moving the order.