As of iOS version 10.3 Apple have added further required steps in order for self-signed certificates to be trusted. In old versions of iOS and Safari, it was enough to download the server certificate and install it, as described in our documentation. Now however, you also have to enable that certificate in the "Certificate Trust Settings" which can be found on bottom of the "Settings/General/About" page.
Added a note for this in our documentation.
Looks good.