C525 + TDS GTN750Xi -- Flt Director twitching

[airforce2]

In the Citation when using the TDS garmin GTN750Xi, in turns the roll bar on the flight director is incessantly twitching back and forth, and the AP is also constantly varying the bank angle, resulting in a small but annoying rapid wing rock.  It appears as if there are conflicting roll inputs fighting each other.  It does it with the UNS on or off.

Any ideas on how to calm it down?