It happened on both, github and launcher versions.
version 4.9.1
Camera actor moves backwards when it is selected and you double click on its name in the list of actors in the scene.
How to reproduce:
Open a project
Drop a camera actor on the scene
In the list of actors inside the level, find the camera and click to select it
Double click that name again
Result: Camera goes back a little bit, messing up the original position.
The cause seems to be that when you double click on an object, the editor shows you that object, but if the object is a camera actor, it will try to show you that camera actor, but you are the actor so it moves the camera to show you that actor (I don’t know how to explain this part better sorry).
This bug is not a big deal, except that it can mess up with camera locations and people might not even realize it and it will keep messing up their matinee cameras.