Due to the number of 520s being reported in similar circumstances, we are escalating the issue to Cloudflare Support. The original incident should have been resolved and your issue may well be unrelated.
We recommend checking these troubleshooting tips, if you haven’t already.
Try the suggestions in this Community Tip to help you fix “Error 520: Web server is returning an unknown error”.
Error 520 is essentially a catch-all response when something unexpected happens or when the origin server incorrectly interprets or does not tolerate a request due to a protocol violation or an empty response. A 520 error occurs when the connection started on the origin web server, but that the request was not completed. The most common reason why this would occur …
If you have been through these thoroughly and are not seeing corresponding issues on your network/server and you have a ticket number with Cloudflare, please reply and post that #.
To enable efficient troubleshooting by support, please ensure you include the following on the ticket:
example URL(s) where you are seeing the error
Ray IDs from the 520 pages
output from a traceroute from any impacted user
example.com/cdn-cgi/trace - replace
example.com with the affected domain.
Also include two
HAR file(s) : one detailing your request with Cloudflare enabled on your website and the other with Cloudflare temporarily disabled - see How do I temporarily deactivate Cloudflare ?