Should the order of objects in the Hierarchy view be stable?

I order things manually in my hierarchy view based on the order encountered in my scene. For example:



While I'm working on a single scene, things seem to be stable in this way. But at some later point, it seems that I'll eventually reopen a scene, and find that the order of the objects has changed, apparently randomly.

Does this sound like a bug? Or is the order of object in the hierarchy view not expected to be stable? (Unity 2018.3.2, but was also happening under 2018.3.0)

 

It's stable for me, so it sounds like either a bug or a rouge asset which mess up your hierarchy.

Also make sure you chose the transform sorting, not the alphabetical.

 

That sorting option is interesting. I don't see that as an option in my Hierarchy window. Is that a script you installed? Based on a search, it seems like maybe some script from this discussion:

https://forum.unity.com/threads/unity-4-5-new-hierarchy-window-sorting.248298/

 

Nope. it's built-in option for a while now. But if you don't have it, probably it's not the culprit.

https://docs.unity3d.com/Manual/Hierarchy.html