Thanks for the file link.
I have confirmed that the Play in studio on my laptop is the same as the video.
My laptop has the following config:
System Model: Alienware 17 R5
Operating System: Windows 10 Home 64-bit (10.0, Build 18362) (18362.19h1_release.190318-1202)
Processor: Intel(R) Core™ i9-8950HK CPU @ 2.90GHz (12 CPUs), ~2.9GHz
Memory: 32768MB RAM
Graphics Card name: NVIDIA GeForce GTX 1080 Dedicated Memory: 8079 MB
What I would do is put some timing checks in.
For example print out the animationtrack.TimePosition within a renderstepped function.
That might give a better understanding of where within the animation its staggering.
I must admin I am not an animation expert but do understand systems.
The more evidence you can collect to better so if no one can give you the answer you could raise a bug report against studio.