It's not a Pi-hole issue, I get the following display without using a Pi-hole DNS Server.
This XML file does not appear to have any style information associated with it. The document tree is shown below.
<Error><Code>AccessDenied</Code><Message>Access Denied</Message><RequestId>152530961DA62CD4</RequestId><HostId>n9/VM4pmsV2z1nUH1ojrzPVYHtvcGNinEoM4VX5mrQ5d/hjUfwSvgaiuUPJ3+ZhdqUXvPDx9Dt4=</HostId></Error>