The Katello 4.4.0 is now available announcement links to a troubleshooting section at https://docs.theforeman.org/nightly/Installing_Server/index-katello.html#Troubleshooting_foreman
First, that’s the nightly docs. The 4.4 and 4.3 docs don’t have anything like that.
Second, it’s the installation docs, not the upgrade docs. For a new installation, I wouldn’t expect any of those problems from the troubleshooting chapter.
So, I think the troubleshooting section should be added to the 4.3 and 4.4 upgrade docs. Where it is now, it’s just wrong…