After upgrading to openssh-8.2p1, the existing SSH daemon will be unable to accept new connections. (See FS#65517.) When upgrading remote hosts, please make sure to restart the SSH daemon using systemctl restart sshd right after running pacman -Syu. If you are upgrading to openssh-8.2p1-3 or higher, this restart will happen automatically.
sshd needs restarting after upgrading to openssh-8.2p1
2020-02-17 - Gaetan Bisson