I have to admit to being somewhat mystified.

Usually, for any facts, the word or two above the Date: box and below the toolbar is the name of the fact.

e.g. Birth, Baptism, Census, Occupation, Death, Burial, etc.

I would expect in your case it would just say: Godparent.

You are saying that instead of a word or two it is displaying a whole sentence such as: “She stood as godparent to John SMITH”.

In Tools > Fact Types… under the Events/Attributes heading, how is the custom fact you created listed?

i.e. Exactly what is the descriptive name of your Godparent custom fact?

Under the Type heading is it an Event or an Attribute?

It would be extremely useful if you could attach screenshots of what you have created as that would avoid a lot of longwinded descriptions.

"A picture is worth a thousand words"