I ran into the same problem, and maybe we have the same scenario.
I understand that you do not want to run the clear method and make the current listed elements disappear, but just make the combo useless.
If before trying to make the combo value empty or empty ("") or ListIndex = -1, you re-populated the combo with a new set of elements, this can happen. Before re-filling the combo box with new items, you must call the clear method, and then re-populating the combo box with new items and then set the value to zero or the value of an empty string ("").
Munim Rashid
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