I don’t know GraphQL well enough to try to help with the immediate problem, but there is a deeper conceptual problem going on here. JSON is not a data type. It is an encoding format. Even though that is the “field type” in the database, you conceptually have some sort of business domain type you are storing that way. That business domain type is what you should expose via GraphQL.
Exposing your field as a “json type” is basically working against the GraphQL goal of specifying your types explicitly. If you are not very careful, this will become a maintenance problem over time.
