The bug was fixed for setting the animation via the StartingAnimation inspector property, I didn't know you were setting it by calling SetAnimation().
When manually calling SetAnimation() after SkeletonGraphic.Awake() you will be too late, as it is updated in Initialize(). From where do you call SetAnimation()? From Awake(), or from Start()? You might want to check your script execution order when calling it in Awake().
Anyway, when setting the animation via SetAnimation() instead of via the StartingAnimation inspector property, we would recommend calling Update(0). I wonder how this worked in 3.7 without the call.
