Well … the cloudfront HTML response may have helped here
Do you use some WAF rules on your cloudfront for security purpose? We do have a few clients referencing this issue (Request blocked) using cloudflare.
This is easily checked by:
Checking your agent for the stats call, and check if your backend is able to send a response (At least, check if the agent is contacted)
Check the CORS request response, and check for headers, just in case the request is blocked by a CDN (X-server, or any other header)
Not sure if it’s related, but looking for cloudflare, it seems like we have a few threads around this topic
