Could you confirm the correct SSL certificate is attached to the HTTPS binding when you click edit on the HTTPS binding?

You can try to remove the existing HTTPS binding, then restart IIS and reinitialize WIE.

Yes the SSL certificate is as expected. 

Is this a Self-Signed or CA Certificate?

Self-Signed Certificate

The initializer usually throws that error if the HTTPS binding has been created for one site and you select a site which does not have any HTTPS bindings configured. I would therefore check again if the selected certificate is actually the one that is created for the correct site.

Another option would be to create a new certificate and run the initializer again, the new certificate will be listed in the initializer, select the new cert and see if that works.

Ensure the certificate is in the Personal Certificate Store and not the WebHosting Certificate Store.

Incorrect:

Correct:

The certificate is in Personal Certificate Store

At this point my recommendation is to open a ticket with support so they can take a look at this and see what's happening.

If you notice the Host name field is blank. Please enter a value in the Host name field. In the WIE documentation for the initialization wizard we have the following note:

Note: If an HTTPS binding has been created for site A and you select site B, which does not have any HTTPS bindings configured, then a warning message appears. You must set up an HTTPS binding manually for site B or select another site.

Ideally you want this to be the FQDN used to access the site which matches the certificate. You can also try using an asterisk (*).

Also,