When waking from suspend, there are 3 error messages appear about Watchdog:
[63660.938812] watchdog: only one watchdog can use /dev/watchdog.
[63660.938816] watchdog: error registering /dev/watchdog (err=-16).
[63660.938819] mei: unable to register watchdog device.
The solution is:
sudo gedit /etc/modprobe.d/blacklist.conf
add the line:
blacklist mei
Save and reboot.
Reference: Watchdog Error Message?