Gateway errors in Streaming API - occasional internal errors

Companies House seems to have an issue with their Streaming API that causes it to occasionally reject requests due to an internal error.

504 Gateway Time-out

Sometimes a good request is rejected with this response (usually after about 40 seconds):

504 Gateway Time-out

html

<html>
  <body>
    <h1>504 Gateway Time-out</h1>
    The server didn't respond in time.
  </body>
</html>

Other times it responds like this (usually after between 5 and 30 seconds):

502 Bad Gateway

html

<html>
  <body>
    <h1>502 Bad Gateway</h1>
    The server returned an invalid or incomplete response.
  </body>
</html>

Another possible error response (usually immediately):

503 Service Unavailable

html

<html>
  <body>
    <h1>503 Service Unavailable</h1>
    No server is available to handle this request.
  </body>
</html>

This doesn't appear to depend at all on the client or the request.

These are some posts on the developer forum from developers who have experienced this error: