Taking the UserDefinedNetworks as an example. If the user doesn't have any UserDefinedNetworks and visit the UserDefinedNetworks tab, it will show No UserDefinedNetwork found and have a link at the bottom redirecting the user to Learn more about UserDefinedNetwork. This link is broken, and redirecting the user to a 404 page.    

4.21 (the doc for 4.21 might not be released yet, so this should be fine for now), 4.20    

Always    

1.visit the UserDefinedNetworks tab
2. click on Learn more about UserDefinedNetwork     

 Get redirected to https://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/networking/multiple-networks, which 404.

https://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/multiple_networks/understanding-multiple-networks should be the working page, based on the behavoir observed in release-4.19    

!!! More broken links might be there, UserDefinedNetworks is just an example.