[#14566] - adhoc view table with two groups and one column

I created a table in an adhoc view of jasperreports server 7.5, with two groups (column1 and colunm2) and one column (column1)
the first group is column1(data: groupA, groupB, groupC...), and the second is column2(data: group1, group2, group3...)

The sequence of group to be active is acttrally firstly column2 and then column1(result is like select column1 from test group by column2,column1) but not expectedly firstly column1 and then column2.

This phenomenon is different from the one of jasperreports server 6.4(result is like select column1 from test group by column1,column2).

I think it is an bug in jasperreports server 7.5. How to fix it?

Thank you!