Spotify: previewUrl is not being saved to endpoint

[djmtype]

For some reason Spotify's previewUrl is not being saved to my query after saving it and creating the handler.
You can clearly see the results in the GraphiQL playground.

However, looking at the results of the endpoint, it's missing.

Oddly, in functions/netlifyGraph/index.js, netlifyGraphOperationsLibrary.graph and index.d.ts, it's also present.