Unable to use a certificate from my Windows CA

I am trying to use my own certificate signed by my CA, instead of the self-signed SSL certificate it offers by default.

In fact, with the self-signed SSL certificate, WAC runs on HTTPS:

However, when I switch to the certificate I have generated in my CA:

When I try to access the link, it returns me:

So if I switch back to self-signed SSL certificate:

The WAC console is working properly again:

What I doing wrong when I generate that certificate?