After SU6, runway steering was erratic or not at all. Also, CH throttle quadrant was erratic, sometimes going to full throttle after landing.  I tried every setting I could find that was related; no joy.

I shut down the computer and pulled all power cords, including powered usb hubs.  When I restarted, MSFS worked perfectly; all controllers functioned normally.  I've used this procedure before and it fixed other unrelated problems.  I'm not sure if this will help anyone, but I thought I'd share.  If you're at your wits end, this is one easy procedure to try.  I'm still not sure why that works and why it has worked with other unrelated problems.

Dave

As a general rule, when all else fails do this. Just rebooting does not always clear the issue, especially with usb ports etc. A complete power down is always a good idea.