Flexbox children taller than content - flex wrap bug with table header [closed]

Flexbox children are taller than their content if set to flex-wrap: wrap and containing a table header that could wrap. Is this a Chrome rendering bug or am I just crazy?

These all seem to fix the issue, I'm just trying to understand why its needed and if this is a bug:

• Set parent to flex-wrap: nowrap;
• Set white-space: nowrap;
• Set child to width: 100%;

<div style="display: flex; flex-direction: column; flex-wrap: wrap"><div><table><tbody><tr><th width="85%">ColumnNoWrap</th><th width="15%">Column With Wrap</th></tr></tbody></table></div></div>