Hi, This is not an issue that causes bugs or odd behaviours in Unity, but rather an issue with source control : A chunk of data was moved around in the file. The data itself has not changed, the prefab itself has not changed, nothing in its behaviour has changed... Unity just decided it wanted to save the thing in a different way. If I discard these changes, Unity will do them again the next time i has the opportunity; if I keep them, Unity might still decide to change things again another time. This becomes an issue when manipulating large scenes or prefabs; it becomes hard to tell which changes are actually relevant to a commit, which are not, and keeping them makes us much more suceptible to getting obscure merge conflicts. From what I observed, this only happens to overriden properties of a prefab; files suceptibles to spontaneous changes are Scenes with prefabs, Prefab variants, and Prefabs with nested prefabs. The one thing I have not been able to figure out is what causes these changes / what decides what order the data is serialized in. Does anyone have any idea ?