Hi Erwin,
Thank you for your interest in Syncfusion products.
Regret for the inconvenience. I am afraid that I am unable to reproduce the mentioned issue in GridGroupingControl, when the Dynamic Filter is used to filter the records in GridGroupingContorl. It takes very less time to filter the records in GridGroupingControl.
Also, in GridGroupingControl Engine Optimization techniques are used yo increase performance for larger data sources. This makes the GridGroupingControl operating with Virtual Mode and there by increasing the performance. For more information on this please refer the below browser samples shipped with the product.
Grid.Grouping.Samples -> Performaence -> Engine Optimization Demo
Grid.Grouping.Samples -> Performaence -> GroupingPerofmance Demo
Please have a look at the above sample and if still the issue exists, could you please try reproducing it in the above sample or send us the reproducing sample so that we could sort out the cause of the issue and provide you a solution? Thanks for providing additional information
Please let me know if you have any concerns.
Regards,
Athiram S