Firebase observer not working, why won't it keep a watch on the value change?

I am trying to set a Firebase observer by calling the following:

ref.child(id).child("isLocked").observe(.value, with: { snapshot in

    print("isLocked = ", snapshot.value!)

})

When the view loads it works perfectly. It prints out the correct value.

When I go change the value either in Firebase itself or on a separate device the isLocked is never printed again. When it should be since I have an observer on the path. What gives?

The end goal here is to have a UIButton available based on if the lock value is true of false.

The view is loaded with the button.isHidden = true.

UPDATE

I found the source of my issue with observer not "Working"

It would seem that there is a timing issue.

In the previous view controller (which segues into the new view controller) I am calling ref.child(pID).child("isLocked").removeAllObservers() in the 'viewDidDisappear' function

And in the new view controller I am 'trying' to setup the same path observer 'ref.child(id).child("isLocked").observe(.value, with: { snapshot in'

which I guess the removeAllObservers() trumps the setup of the new observer!? How do I get over this!?