DCV Error - AutoSSL

The system failed to fetch the DCV (Domain Control Validation) file at "http://example.com.au/.well-known/pki-validation/9AD3C48C5FC00968B8BCBBC4C7F4404E.txt" because of an error: The system failed to send an HTTP (Hypertext Transfer Protocol) "GET" request to "http://example.com.au/.well-known/pki-validation/9AD3C48C5FC00968B8BCBBC4C7F4404E.txt" because of an error: Could not connect to 'example.com.au:80': Network is unreachable . The domain "example.com.au" resolved to an IP address "xxx3:1400:2:1:0:0:0:107" that does not exist on this server. DNS-based DCV also failed.
Please help. Thank you :)