Unfortunately we've not found time to look at this issue. If something is urgent for you, you can attach the source code of Radzen.Blazor to debug your case - you can even submit a pull request with a fix. Paid support is also an option, check our pricing page for reference.
Using UtcDateTime sub property of the DateTimeOffset when specifying RadzenDataFilterPropertyProperty will resolve your issue.
Thanks, I'm raising a purchase request to get paid support as I'm very impressed with the component set and definitely see extensive use of the range in the future of our product.
I've had a look and the issue seems to be that the RadzenDatePicker for a DataFilter always returns a DateTime regardless of the bound property type meaning the resulting CompositeFilterDescriptor is also of type DateTime. This then causes an exception in
public static IQueryable<T> Where<T>(this IQueryable<T> source, RadzenDataFilter<T> dataFilter)
Here is some example code required to replicate the issue: