Cannot query field "X" on type "Y"

OK so I’ve just added a new field “X” to an object “Y” in my realm schema.

The new field now appears in the graphql schema in the web UI. I can go to the Realm (now App Services) web UI, go to GraphQL and use the GraphiQL interface to confirm I can query my new field. It works, fine.

When I try to query the new field in my client javascript app using apollo however, I get the error Cannot query field “X” on type “Y”.

The only mention of this error I can find in the forums is this one, but I think the solution suggested is for an older version of Realm.

Is this a schema caching issue? How to I clear the schema cache in the current latest version of realm?

What I’m trying to do is so simple. Am I missing something here?