We’ve encountered an issue when using cutscenes that are in prefabs. What we’re seeing is:
1. You edit an existing cutscene (e.g. drag things around on their tracks)
2. When you press play, it reverts back to the last-saved state (i.e. those changes are lost)
To prevent it, you have to apply the prefab changes before pressing play.
This issue was fixed in the latest version of Slate 1.7.2 that is currently on the asset store.
If you are not using the latest version, can you please update and let me know if the problem is solved for you?