I ran into the same problem. What you need to do is put the text in another div that has an overflow style. Inline-flex does not support text overflow, as shown here: https://bugzilla.mozilla.org/show_bug.cgi?id=912434
This should work:
<div class="parent-div"> <div class="text-div"> Ellipsis' are cool. </div> </div>
If the text-div style looks like this:
.text-div { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 200px; }
And parent-div:
.parent-div { display: inline-flex; }
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