Hi, I am too experiencing the same behaviour described in this report on two of my systems, but I it doesn't stop when I restart systemd-logind. It also seems to randomly occur after restarts, the 300 logins earlier seem like a good estimate. Commenting out the pam_systemd module in /etc/pam.d/common-session fixes it, but I would prefer a cleaner solution.
Jun 21 17:38:29 mt-mikey sshd[26999]: pam_unix(sshd:session): session opened for user xxyy by (uid=0) Jun 21 17:38:54 mt-mikey sshd[26999]: pam_systemd(sshd:session): Failed to create session: Connection timed out Regards, Philipp