Why did people not “obey” Angie initially?

Angie was an exceptional catheterization laboratory technician who was respected by her teammates. When the director of the cath lab took another job, Angie was the natural choice to take the director’s position.
She was asked to step into the role but with an interim title. Within days, she was in my office to discuss why her coworkers wouldn’t follow her direction. It was her opinion that she needed the permanent title for anyone to listen to her. She kept having to tell people, “This is what we will do, because I am the boss.” They would nod their heads as if they agreed, but often they did what they wanted anyway.
I explained that, instead of using the interim title as a stick to beat over their heads, Angie should look for common challenges and frustrations that they could solve as a team. Most certainly, there would come a time when tough decisions would need to be made and her role and title would be necessary, but day-to-day collaboration was the best way to solve problems and make decisions. The team would learn to trust her judgment, and when a crisis came, they would respect her decision about how to handle it.....