Hello, I just bought the 707, I have noticed that it has some issues with the way the Autopilot handles the turns and pitch trim, I have also read all the posts regarding this matter, I would like to know if anyone did happen to find a proper solution to the problem, what I noticed is this:

When I engage the AP channels, both aileron and elevator the plane tends to immediately pitch down, the plane has already sufficient speed and alt to be flown by AP, that is V2+10 and even more.

On turns either with the knob or with the HDG switch it looses altitude in an exaggerated way, the trim is unable to keep it with the nose up.

the FD indicator on the Artificial Horizon shows the angle of attack way far from what it should be, sometimes gets stuck and have to click a lot on the AP knob to get response, otherwise it will climb to the point of stall or it will dive, I have also checked and unchecked the FSUIPC trim box and no apparent results.

Any input will be Gladly appreciated, Thank you.