Apollo Studio sandbox preflight for introspection fails

Hello,

I’m having an issue with the Studio sandbox. I can succesfully inspect the schema and query for data, but if I look in the network tab, every inspection query (polled every second) sends a preflight request that fails:

I see the IntrospectionQuery firing and getting a 200 OK with data, only to be followed by the failing preflight request just after. I’m fairly certain it is related to the introspection polling, as the failed preflight requests are shown alongside each introspection query fired every second while auto updating is turned on. If I disable schema polling, the failed preflights also stop.

Am I missing some header or something? CORS seems to work seeing as I can both introspect and fetch data. I couldn’t find any meaningful tips by searching online.

Thank you!

Same - also encountered as part of this Sandbox Behind Reverse Proxy

Can you share a reproduction? At the very least, what version of Apollo Server are you using and which integration? We can be helpful with additional information about how you’re getting your error.