DropDownList and MulstiSelect do not open on click(IE 11).
They do open sometimes, but it seems random.
They do open when using the keyboard.
I got this to happen by putting the ComboBox inside a <label> element, e.g.
<label className="form-label">
Please select:
<ComboBox className="form-control" data={['alpha', 'bravo', 'charlie']} />
</label>