Hello Leonid,

I have been investigating into the behavior you are seeing where the first grouped record of the XamDataGrid is expanded, and I was unsure if you had meant updating the existing data source of the grid or switching it out to a new collection, so I tested both options. In doing so, I am unable to reproduce the behavior you are seeing.

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 DLL versions we are using.  My test was performed using version 21.1.20211.27 in Infragistics for WPF 2021 Volume 1.

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 you have any other questions or concerns on this matter.

XDGGroupExpansion.zip