if I put a listbox control inside of a div of 200px in a flexbox column that is, say 220px, a wrapper of the listbox adds about another 100px to it's width, and thus a horizontal scroll bar. It looks terrible.
(the same thing happens if I put the listbox control inside a CSS grid section).
Looking at the source code in Chrome dev tools, I see, just below element.style{}, there is:
e-listbox-wrapper:not(.e-listbox-container)