Are you a leader or a manager? That is the question one needs to ask when they are part of a project management office, project, task team, or group. Working on the PMO and working in the PMO are two different things. Leading requires setting direction, allocating resources, and inspiring action. If you are not doing these three things, you are working in the PMO.
A leader, a Manager, an Operator are all titles. they are all designations that convey some sort of authority, but they are still what people are.
Leading, Managing, and operating, these tell people what you do. They are action words. Doing these things is not determined by what you are called. There are Leaders that just operate in a PMO and there are project managers that lead other around them.
Take a moment to determine if you are leading or are you just the leader. You might see that operating and managing are what you usually do. Working like this is certain and safe. Leading is ambiguous and offers great opportunities to look bad, but the rewards can be great.
There is not right timeframe that you need to lead and to operate. Find opportunities to lead, the people in the organization will thank you for it.