The Next.js samples for preview mode involve doing a redirection from an api route. The code is something like:

  res.setPreviewData({
    maxAge: 60 * 60 // The preview mode cookies expire in 1 hour
  })

  res.writeHead(307, { Location: `/${req.query.contentType}/${req.query.slug}` })

I can do this from next run, but if I try this on Netlify it seems to strip the location header on the 307 redirect. Is this something to do with the compat call or am I doing something wrong?