Are you using gnome-keyring? (I think that's the default). If so, gnome-keyring doesn't actually implement ssh-agent locking although it will claim to work.
https://git.gnome.org/browse/gnome-keyring/tree/daemon/ssh-agent/gkd- ssh-agent-ops.c#n1417 op_not_implemented_success, /* GKR_SSH_OP_LOCK */ op_not_implemented_success, /* GKR_SSH_OP_UNLOCK */ -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/965836 Title: `ssh-add -x` does not prevent key use To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/965836/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
