Can’t move hierarchy to collection or parent in outliner I have this one chain hierarchy in my outliner and it doesn’t move to the collection when I parent it to an object in that collection. Even if I try to move it manually it just stays there outside the specific collection in the Scene Collection.

Here I have a collection FISHING BOAT and an empty that serves as a parent for all the parts. When I try to parent the chainlink hierarchy to the empty or move it to the FISHINGBOAT collection, it just stays outside.
What is happening here?
Thank you very much in advance for any ideas or insights!
An object(A) in a certain collection (lets call it Collection 1) can be parented to an object(B) in another collection (lets call it Collection 2), while it(A) remains in Collection 1.
So what you are experiencing is normal/intended behavior.
If you want the child(A) to also be in the same collection as its parent(B), simply select the object(A), press M to move it to another collection, and choose the one the parent is in (Collection 2).