First do you use IPv6? If not, make sure that it is not enabled (Uncheck “Enable IPv6”)
Else if you use IPv6 i’m not sure how to fix the error i had the same error a some point:
But i’m unsure if i still have the issue.
So try and look under the “Host” tap then click on your server, under “Public Address” and “Public IPv6 Address” use your FQDN for the server (Not ip-adresses) also set “Local Address” and “Local IPv6 Address” (Here use IP-addresses)