No Boss, for me its not,
I followed the following steps to test:
1. Expand first row
2. In child grid textbox , i typed something
3. i collapsed that first row
4. re-expand first row
5. data typed in textbox is lost
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1. Expand first row
2. type data in textbox of childgrid of first row
3. click on button
4. first row gets collapsed on button click automatically
5. expand first row
6. comma gets prefixed with data typed in step2
Thanks for giving my problem your valuable time.
Plz rechk