I'm developing a web application which uses certificates for authentication and I recently moved to http2. Inside my web application, every project has a different subdomain. If someone hasn't any valid certificate, he can access the first subdomain without problems, but if he changes subdomain, he gets a 400 error. On server side I get a "client attempted to request the server name different from that one was negotiated while reading client request headers". I think that the client shouldn't use the same http2 connection when the sudomain changes. In fact, when there's a valid certificate, if the subdomain changes, the certificate authentication is required again and everything works fine. The problem happens only when there's no valid certificate and I need unauthenticated client to access my web application, even if with different permissions. Firefox should open a new http2 connection for the other subdomain. Thanks in advance.