I have had an issue similar to this. After I am on ILS and Glide, when I turn off AP and AT, the place goes crazy. First thing is it pitches up hard with no control over it. The trim on my yoke has no effect, though I can manually turn the trim wheel with the mouse, although I never get it under control as it will enter a dive. No control over throttle and, of course, the AP / AT will not enable.
I fly only long haul and 99% of the time that would be in a PMDG aircraft because they just work as they should. It is beyond frustrating to get within sight of the field only to turn into a grease stain. I think this happened in the 787 last time I flew it last week.
I did not have this experience before the latest update. I can try something if you need, just ask.
Thanks