Cross reference mess in Timelines

I’m using timeline to create intros for each level of my game. Each level has a Timeline asset. Each timeline asset has several TrackGroups (1 per character) and each TrackGroup contains several Tracks.

I have, at some point duplicated a timeline asset (e.g. duplicated Intro_01 and renamed it into Intro_02). It looks like the duplication is not « clean », and when I modify my asset Intro_02, some changes are saved in Intro_01 and maybe vice-versa. Although from an external point of view it works (I see what I expect when I open both Timelines in Unity), it is very hard to work in these conditions. In particular when several people are working on making timelines and end up with unexpected conflicts when they try to commit their work.

Is this behavior normal? Is there a way to break these cross references and make sure each asset is only saving the stuff it should save?