Control Scheme
Play with the Free Camera toggle to correct your mouse movement. Holding right click turn will rotate you and your toon, while left click rotate will rotate only your camera. If you JUST left click or right click, it will switch between those two modes so after you start moving forward, your camera will either follow or watch from a fixed angle when you turn.
You can use both buttons to move at the same time, but I believe you are stuck in the following camera mode with that…