Niko on 18 Jan, 2017 10:55 AM
I think I have found the cause of this issue.
It happens when you start a timer for a task while the menu bar is not visible.
The menu bar is not visible when you are currently in a fullscreen app or when you have enabled “Automatically hide and show the menu bar” in macOS System Preferences.
Do you think this was the cause for the bug you reported.