I saw 2 posts already but none of them provided any info about what happened.
Context:
I am trying to get my website listed on Baidu search engine. However Baidu is saying they cannot list our url because it is not reachable by them. Here is the error they reported:
HTTP/1.1 520
Date: Wed, 28 Jul 2021 17:01:01 GMT
Content-Type: text/html; charset=UTF-8
Transfer-Encoding: chunked
Connection: close
CF-Ray: 675faac248c436df-LAX
Cache-Control: no-store, no-cache, must-revalidate, max-age=0
Expires: Thu, 01 Jan 1970 00:00:01 GMT
Set-Cookie: cf_ob_info=520:675faac2568b36df:LAX; path=/; expires=Wed, 28-Jul-21 17:01:31 GMT
Set-Cookie: cf_use_ob=443; path=/; expires=Wed, 28-Jul-21 17:01:31 GMT
SG-Optimizer-Worker-Status: bypass
X-Frame-Options: SAMEORIGIN
Expect-CT: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
Report-To: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=taEjBzx0e5%2B%2BfnIzo8xpPDpceEyH8FRShcb96y10hJ0%2FcfK6nQfEWwgrRqJecG43osRQx4dYwoXP82hihwqcBoDYIg9ZDM%2BEBfDEOAC8H5MWeXfy1oCSOEV3MiuypFQ%2BWe8ZBh9M8UA%3D"}],"group":"cf-nel","max_age":604800}
NEL: {"report_to":"cf-nel","max_age":604800}
Server: cloudflare
alt-svc: h3-27=":443"; ma=86400, h3-28=":443"; ma=86400, h3-29=":443"; ma=86400, h3=":443"; ma=86400
However, the website is clearly reachable by us in the US.
520 is unknown error right? What steps can I take to further figure out what happened?
Thanks!