Spine animation is shaky on big iPhones

DoctorZoidberg

I am using Spine 3.6.53.Pro and exporting json and atlas for Stencyl (build 9922) for making a game.
When I test the game on my computer via Flash it looks fine, it also looks fine when I test on iPhone 5s. The problem happens when I test on bigger iPhones like iPhone 6 or 7. The same animation looks shaky. I don't know what happens, but I assume the problem happens when the game is scaled for bigger screens.
Here you can see the recorded video of this animation.

You can notice that the face of the guy on the left is shaky and it happens somewhere on the end of the animation. If you look on the screenshot I attached you can see that the animation is quite simple and this shaky moment happens somewhere on the keyframe 40. I tried to split the assets and add more keyframes etc. nothing works.

Here you can see how this very same animation looks on iPhone 5s. Move the trailer to 46 second, please.

Mario

That indeed looks like a bug. However, we are not maintaining a Stencyl runtime. Could you point me to the runtime you are using? Most likely the authors of that runtime simply need to update to the latest spine-as3 runtime to fix this.