Hi Maheshkumar,
Thanks for contacting Syncfusion support.
We have able to reproduce the reported issue with v14.4.0.15 but this issue was fixed in v14.4.0.20. For your reference we have attached the working copy of our sample in the below link. If you are facing the same issue in v14.4.0.20? please revert us by modifying our sample to replicate the issue. Otherwise please share your sample, that would be more helpful for us to proceed further.
Also RowHeader was not showing while we have dataGrid.ShowRowHeader = false in SfDataGrid.
Regards,
Ashok