Graphql playground works in incognito only

Has anyone else experienced a problem where the graphql playground freezes up in a standard Chrome window, but if you open it in an incognito window it works? By “freezes up” I mean I cannot edit queries or anything else. Clicking into the editor gets no reaction. The playground displays fine and I can open/close Docs, Variables, Explorer, etc.

I assume this is related to authentication, but I don’t understand why. There is an error in the console, "Invalid JSON. Expecting string, got } ". But I’m not sure that is directly related.

Posting this here in case anyone else has this problem.

I am not sure how I jammed up the Graphql playground, but to unjam it, in Chrome, I went into inspector → application → Local Storage and deleted all the stored values there.