I have a combo-box box in a grid where I expand the combo box when editing starts (see attached code).
If you do type-ahead selection (as shown in the first diagram) the drop-down will shrink just to the values that meet the type ahead criteria (in this case just red, since that is the only value in the drop-down that starts with 'r').
Now if I select on a different row's color, red is the only option (see second screenshot).
If I don't do the expand, everything works fine.
How I expand is as shown. If I try different Schedule commands, they all have the same behavior. This seems to be the one that works the best (others tend to flicker the drop-down in the upper left corner of the browser).