$scope isn't disconnected from the $watch cycle

This page says that when a view is navigated away from, the $scope is disconnected from the $watch cycle.
However, I have a tab that temporarily have a lot of watches (which slows down the app), and when I leave the tab - the apps stays slow, which means the watches are still being watched.

Is this a known bug?
Thank you

Have you found a solution to this problem? I am seeing the same problem and it is causing my app to really slow down.

No solution yet as far as I know