When initial grouping is set through the state, the GroupFooterTemplate does not render. One has to perform some action for refreshing the Grid in order to display the template - for example, collapsing/expanding a group.
For reference, the GroupHeaderTemplate renders correctly.
Reproduction: https://blazorrepl.telerik.com/wRaJFgFy10vagYnf05
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ADMIN EDIT
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The GroupFooterTemplate renders with a delay after the Grid. A possible workaround for the time being is to refresh the Grid after it has been initialized to ensure the GroupFooterTemplate will be displayed.
Hi Pavel,
I'm glad to see that the provided workaround of rebinding the Grid serves as a good temporary solution for you.
Regards,
Hristian Stefanov
Progress Telerik