How to debug HttpModule with SSL?

I am writing a custom HTTP client in C++ using the FHttpModule class. That is working fine, I can connect to the remote web server and do my things. However, as soon as I try to connect to the SSL version of the same web server on the same address (via a “http” URL), the connection cannot be established any more.

Unfortunately I cannot find a way to debug the SSL part (or in fact anything in the FHttpModule class. How is one supposed to find errors in HTTP connections, in particular for SSL connections?

Thanks in advance!

PS: I can connect to that HTTPS web server using the browser quite fine.