When I select entire column and click Sort Ascending on a toolbar, the
heading row I have is recognized in half cases and is not recognized in
another half. When it's not recognized, header row is considered as a
data and moves to the bottom of the table. This happen even when I
don't change the selection and it remains as entire column. First row
is freezed, if it does matter.

Data | Sort... seem to work fine, but maybe I didn't give it enough
attempts.

Any ideas on making toolbar Sort more consistent?

Thanks