Search results miss double colon between tld and port

We run the suite on port 8443 restricted access. After the upgrade to 7.12 we have the issue now that when we search (not using elastic) we get the results but in the URL of the link the double colon is missing between the tld and the port 8443

shot
Any idea, as on 7.10.31 we had no issue. That was the version we upgraded from.