With the 1.9.3 update, the CJ4 autopilot now has the same oscillations that were present in an earlier version. AP was fixed and now the same problems have returned.
On climb after takeeoff, the nose oscillates up and down. At VRef speed during ILS approaches, the nose oscillates.
Any cruise above FL370 is unstable and cruise at any altitude with turbulence induces aircraft oscillations when AP is on. As soon as AP is switched off, oscillations stop.