"The "Strict-Transport-Security" HTTP header is not set to at least "15552000" seconds. For enhanced security, it is recommended to enable HSTS as described in the security tips ↗. Your web server is not properly set up to resolve "/.well-known/caldav". Further information can be found in the documentation. Your web server is not properly set up to resolve "/.well-known/carddav". Further information can be found in the documentation."   These are the messages I get in my next