Why doesn't the desktop app follow my call-forwarding rules?
Call forwarding schedules are created based on a specific phone number. However, since the Grasshopper desktop app is not tied to a specific phone number, it is unable to respect specific call forwarding schedules. Once you're logged into the desktop app, we'll always try to reach you there.
If you do not want to receive calls outside of your call forwarding hours on the desktop app, you'll need to turn on do not disturb or log out of the desktop app altogether.