Sorry for the trouble! Thanks for the email, we received the reproduction project and are currently having a look at it. I will get back to you as soon as we have figured out what is going wrong.
The problem is that you are destroying and re-instantiating the SkeletonAnimation GameObject. Since you first instantiated the GameObject with the SkeletonAnimation component and a certain first animation and then re-initialized the component in a coroutine method, you are missing a call to animation.Update(0) after the initialization. Otherwise you always see the first frame of the instantiated GameObject before changing.
So simply add:
ani.Initialize(true); // below this line
ani.Update(0); // add this line