tuanttbcr I'm sorry to hear you're having trouble. I am afraid that I cannot quite figure out the cause of the problem from the video alone, so could you please send us a Spine project that can reproduce the problem?: contact@esotericsoftware.com
We would appreciate it if you could send us a minimal version of the project, removing any items that are not relevant to reproducing the problem. Please briefly mention this forum thread URL in the email so that we know the context. Then we can have a look at what's going wrong.

My guess is when you look at the animation by dragging the timeline, it looks like you want because you are seeing the poses at full frames, where you have keyed the poses. When you play you will also see interpolation between frames. To set the timeline between frames, hold shift while you are dragging the timeline position. See this section and the Frames section after it:
http://esotericsoftware.com/spine-keys#Timeline-position

You could change your keys to stepped, so you don't get interpolation, or you may be able to animate things differently so you get the look you want from the interpolation.

Note if you are using deform keys, you probably want to avoid them:
https://esotericsoftware.com/spine-keys#Deform-keys