Acrobat sign API: certificate warning

Hello,

I'm using the Acrobat Sign API to create some signing request. Everything works fine, except that I'm getting a warning at the first API call: "Hostname/IP does not match certificate's altnames".

I'm using 

http.Open "GET", "https://secure.api.eu2.echosign.com/api/rest/v6/baseUris", False

I checked the certificate and we can find DNS Name=*.eu2.echosign.com in subject alternative name, so I'm a bit confused about this warning trigger.

This is not a big deal as I could bypass the name verification, but I'm probably missing something. So if anyone can explain why I'm getting this warning, that would be great.