Symptoms:
Selecting the Pause/Resume button in the tray monitor results in the backup not restarting.
Solution:
The intended behavior of this option is to pause and resume the protection plan. In progress backups will be stopped when the button is selected and will prevent plans from starting until the designated time. Selecting resume will reapply the protection plan and the next scheduled backup will run at it scheduled time, any missed backups from a time when the protection status was paused will default to their next scheduled run.