This issue can be reproduced using the Form Validation - Form Layout demo.
DateEdit for Blazor inside the default EditForm component - Clicking the "Today" button leads to the "Value cannot be null. (Parameter 'accessor')" error
Answers approved by DevExpress Support
We have fixed the issue described in this ticket and will include the fix in our next update. The update will be available via the DevExpress NuGet server. Refer to this page to obtain your personal NuGet feed URL.