RHEL 8.6 Server Cannot ssh into the server without upgrading openssh-server

Hi, I am a new user of RHEL.
I found that I cannot log into my RHEL 8.6 server without upgrading the SSH server on it. Of course, I tried to restart sshd and do other things, but all failed. But after upgrading the openssh-server package using dnf, it works again.
I wonder whether it is designed so? How can I know when I should upgrade some basic packages?