How are “Auto” and “100” Percent Row Height different

An “Auto” row is sized to the smallest height required to display the text.

If the enclosing Header or DataRow is a fixed height, the TextDataCell will be drawn starting at the top and may be smaller than the full height allowed (even with Center vertical alignment).

With a 100% layout row, the TextDataCell will be sized to fill the entire height allowed by the Header or DataRow.

So if you want a centered vertical alignment in a fixed container, be sure to use 100% and not Auto in the layout row. (Alternatively, you could use Auto and supply top/bottom cell padding to appear centered in a larger box).