wixEvents.getForm(eventId) returning error

I’m completely bamboozled by this. I’m trying to retrieve the form for a published event but it’s just returning this error.

Error: Ambassador client request failed: HTTP STATUS: -1 
RESPONSE: "Failed to fetch" 
See the httpStatus and response fields for more information.

I’ve stripped everything out and the error is being caused by

  eventId="f58c2211-bb64-4d86-82fb-433eb709adfb";
  wixEvents.getForm(eventId)
  .then((result) => {
    console.log(result);
  })
  .catch( (error) => {
    console.error(error);
  })

Can anyone offer a cause or even a clue as to what might be going on?

I’ve just tried on the published site and it isn’t working there either.
I know there was a bug with wix-members.getMember last December which was giving the same error error but I can’t find anything showing how that was resolved.