In all cases of selection (by mouse or keyboard) in QTableWidget, at first currentIndex() change,
then selectedRows() change.
But there is another case when this sequence dont work:
At first selectedRows() change, then currentIndex() change.
Example:
selecting only by mouse several elements on QTableWidget

How to:
example show currentRow() when selection changed
only in one case currentRow() returns previous value
when you selecting only by mouse several elements on QTableWidget