Hello aliaksei,

Thank you for posting in our forums!

I followed the steps you suggested and was unable to reproduce the behavior you're describing.  I set up an igHierarchicalGrid with several columns and enabled the GroupBy and Sorting features.  In my sample, I dragged the Name column and then the Description column to group by them.  I then click on the "Test" column twice to sort descending.  I remove Name, and then Description from the grouping and the Test column is descending sorted.

There may be a difference between the data types in the columns which is causing this difference between us.  Knowing which datatypes you are using could help reproduce this.

I have attached the sample project I used to test this.  Please test this project on your PC; whether or not it works correctly may help indicate the nature of this problem.

If the project does not work correctly, this indicates either a problem possibly specific to your environment, or a difference in the library versions we are using.  My test was performed using IE10 with version 13.2.20132.2212 in IgniteUI 2013 Volume 2.

If the project does show the product feature working correctly, this indicates a possible problem in the code of your application.  It will help if you can provide a small, isolated sample application that demonstrates the behavior you are seeing.

Or, if this sample project is not an accurate demonstration of what you're trying to do, please feel free to modify it and send it back, or send a small sample project of your own if you have one.

Please let me know if I can provide any further assistance.