In your demo page: https://blazor.radzen.com/datagrid-group-header-template
The "All groups expanded" function doesn't work properly.
After the page loads, the control shows the minus box. Clicking it changes to a checkbox, but has no bearing on the data grid. A second click does collapse the grid and changes the the control to an empty box. From there on, the visual state of the expand control changes, but does not affect the grid. Once it's in this state, clicking the arrows on the grid rows doesn't work anymore.
I had the same experience in my local environment using both Chrome & Edge. Without the expand option, the grouping works beautifully.
I just got started with your components 2 days ago and I already love your data grid! - and so do my users!
Using Blazor .NET 7.
This is how three-state CheckBox works. The minus state means null, after the first click the state goes to true (checked) and all groups will be expanded however since they are expanded by default there is no change in the DataGrid, the second click will change the CheckBox state to unchecked (looks empty)/false and all groups will be collapsed.
Enchev, you seem to have only half read what I posted, and you obviously didn’t go to that page and investigate the function of your demo.
So to the rest of Radzen, that demo page could use a look. I had asked some of my teammates to check it and they had the same experience I described.
Since I’m the author of the demo I’ve tried to explain how it works. You can try to collapse one of the DataGrid items before checking the ChecBox to see how the DataGrid will behave. Feel free also to submit pull request with your proposal how the demo should work.