Greetings from the Syncfusion support,
Based on your requirement we have prepared a sample of virtualization with grouping and binded the local json datasource to the Grid. The grouped items are collapsing properly from our end. Please refer the below sample for more information.
Limitations of virtualization with grouping.
- The collapsed/expanded state will persist only for local dataSource while scrolling.
- Grouping with virtualization feature was not supported while using remote service.
- Grouping module collapseAll() method was not supported with virtualization.
If you still have the issue, please share the below details that will be helpful for us to provide better solution.
- Please confirm your package version.
- Please confirm you are using local data or remote data.
- Please share your complete grid rendering code.
- If possible please reproduce a issue with our above attached sample.