Typically this is caused by a mis adjustment.
My garage door trolley is stuck.
The garage door opener motor will hum when attempting to open or close the door but is unable to travel due to being lodged against the bolt tab.
A door that is stuck halfway open is a security risk allowing access to the garage and the home if it.
Over time your garage door track can be damaged resulting in a garage door that gets stuck open.
If you detect a small bend you may be able to straighten it out yourself but anything more extensive will require professional intervention.
Surprisingly your garage door just being locked can be causing your problem.
Some garage doors have a full lock system which enables you or anybody to lock your garage door from the outside by only turning the handle.