@RFpilot Are you leaning the mixture at higher altitudes? At high altitudes, the mixture needs to be leaned (by pulling the red lever back) because there is less air up there. The engine will lose power if it's not leaned properly. Generally you want to aim for peak EGT (look at the EGT gauge near the throttle levers) for best economy or peak EGT + 100 degrees F for best power.
Almost the same issue here. Using the Turbo Arrow IV in P3D 4.5 with the latest hotfix with a balanced load and fuel but my aircraft banks to the left at least 10 degrees with the yoke centered. I don't have this issue with any other aircraft such as the A2A planes or the JF 152...or any others for that matter.
I am aware of the right rudder needed on take off/climb but my banking issue persists even at 9,000 ft cruise and all other altitudes.
(page 67 in the manual) ... "As you approach 4,000ft, place your mouse cursor over the navigation/approach coupler knob and press the middle button on your mouse (this is often integrated into the mouse-wheel). Alternatively, you can use the default key assignment – [Ctrl]+[Z].This toggles altitude hold mode. The autopilot will capture and hold the current altitude (rounded to the nearest hundred feet). A tooltip indicates whether altitude hold mode is engaged.
... The real-life Piper AutoControl IIIB doesn’t feature altitude hold mode but it has been included for convenience".