well, SSL has to work for the hostname in question. Usually HTTP 5xx errors are due to SSL not in fact being well configured at the URL (or timeouts, or other server issues on the remote site).
If you could give me the x-nf-request-id for a failing call, or the URL of your proxy that demonstrates the problem, I can look in our internal logs to try to determine what is happening.
Hi, @bravokeyl, I do see there was a 500 response returned for that x-nf-request-id when an attempt was made to proxy to another site/service. The error message was:
x509: certificate signed by unknown authority
So, it was an SSL error from the proxied endpoint which caused Netlify to return the 500 response. If there are other questions about this, please let us know.