Hi Rachael,
We couldn't able to reproduce the issue as you mentioned. We created one sample in which the GridGroupingControl is placed inside web page. And we populate the Grid data from the AccessDatasource. We afraid it doesnt reproduce any issue even if we click the GridGroup. To ensure this we have attached our sample. However could you please send us the sample which causes this issue. It will help us for further investigation.
FocusingGridIn the mean while Please download our sample and do let us know if you are able to reproduce the issue.
Thanks for using Syncfusion products.
Regards,
Gokulkumar.B