Hi Arkyadeep,
After analyzing your OML, we have verified that you are being affected by an issue that we have already identified internally and we have added the fix to the Grid.
The issue is related to a conversion of values for comparison, it is being performed poorly and directly affects the GetRowNumberByKey action. For now, we don't have any workaround that doesn't require cloning the component and changing the grid core.
In the next release this issue will be fixed by default. After the release, please update the Grid to the latest version and check if the issue still happen.
Thanks