DidYouMean doesn't give any suggestions

[haspe85]

I have a property that has the attribute DidYouMeanSource

[Display(
        Name = "Rubrik",
        GroupName = SystemTabNames.Content,
        Order = 1)]
    [DidYouMeanSource]

    public virtual string Heading { get; set; }

But the search result doesn't give any suggestions back.

if (result != null && result.DidYouMean != null)
            {
                searchResult.DidYouMean = result.DidYouMean.FirstOrDefault();
                return searchResult;
            }