I have been trying to send HTTP requests to the Azure Search Service REST API. However I keep receiving a response with error code 522.
I know that 522 occurs when server is overloaded. However I don't think that is the case here.
Azure Search service never returns HTTP code 522. After a quick web search, it seems that 522 is used by infrastructure vendors like CloudFlare - are you using CloudFlare or similar by any chance?
Please check for routing and DNS resolution issues in your network infrastructure. If it's a newly created search service, DNS propagation may take some time. Can you ping your search service?