In our latest version Sitefinity 6.3 there is an issue with forms notifications, and we are already working in order to resolve it. Excuse us for the inconvenience. You could workaround this issue by creating a second form. You will need to subscribe to this new Form, and discard the first one.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items