Make sure your controls are assigned in ChasePlane and removed from FSX/P3D and FSUIPC
ChasePlane uses it's own controls to move the camera and cannot use the ones set in FSX/P3D.
Make sure you remove any conflicting assignments in P3D/FSX and FSUIPC and set the necessary ones in ChasePlane > Preferences > Control Assignments for ChasePlane to work properly.