Hello Min,

Thank you very much for provided information.  I was able to reproduce this issue and I`ll log this behavior in our internal tracking system. I created a private case for you with reference number CAS-127822-M5Y5D4. You could find this case at https://ko.infragistics.com/my-account/support-activity/ .  I`ll send you more details through this case.

Please note that product lifecycle of your version is expired  https://ko.infragistics.com/help/product-lifecycle/ and our fix will be include only in supported version.

If you have any questions, feel free to write me

Regards