Foreman proxy - puppet4 CA hosts are not being assigned puppet master

Hello,
We have an old puppet4 env with puppetca & puppet foreman proxy installed.
All hosts from that environment are not being assigned the puppet master even though puppet_server fact is present.
Also, on the proxy->puppet->general tab is empty

No any issues with puppet5 environments though.

We’re running foreman 1.16.2

Thanks

Any suggestions?