Sorting is not working properly

The sorting is not working correctly for numbers with comma (,) as decimal point and dot(.) as group digit.

and the sorting of dates, when the format is dd/mm/YYYY, is similar to str sorting.

How to resolve this issue?

The sorting use default javascript functionality to convert data to sortable types

For numbers it use parseFloat, which not works for numbers with comma
For dates it use Date.parse which can recognize only dates in standard format.

In both cases you can define custom sorting routines which will sort data in any custom way. ( You can check samples/pro_sort.html as example )