Hi Michael,
Thanks for contacting Syncfusion support.
Please ensure that which platform you are using either ASP.NET Classic or ASP.NET MVC Classic. Because in ASP.NET Classic only we have spell checker support and in that too we don’t have a functionality for the auto spell check option. So, we will consider this as a feature and implement this in our future samples.
Please let us know if you have any queries.
Regards,
Dhivyalakshmi.