I isolated the problem down to an incompatibility between xfce4-power-manager and systemd. When the suspend timeout is reached or the lid is closed, the network manager is being woken before the system has suspended which causes it not to wake on resume.
Switching from systemd back to Upstart fixes the problem.
I isolated the problem down to an incompatibility between xfce4-power-manager and systemd. When the suspend timeout is reached or the lid is closed, the network manager is being woken before the system has suspended which causes it not to wake on resume.
Switching from systemd back to Upstart fixes the problem.
https:/ /wiki.ubuntu. com/SystemdForU pstartUsers