You notice that there are issues subscribing to your lists from Windows workstations using Firefox or Chrome. Firefox and Chrome appear to fail to resolve the list server's location and update the URL in your subscription invitations to HTTPS, which fails because you do not have a certificate installed. Using Edge on the same workstation proceeds normally.
The recommendation for avoiding this situation is to install an SSL certificate. Follow the steps in Install or Update SSL Certificates in Lyris LM to install your SSL certificate. If you receive the message "Your license does not allow SSL", contact the Sales Team to get a quote to have SSL enabled for your LM License.