Just a follow up on that last post...
According to the C3 manual, it is advised to only publish C3 games using the "V-sync" option for Framerate control.
I'm not sure why Spriter animation glitches are occurring at the end/last keyframe of
animations in C3 as it is not an issue in an identical build of projects in C2.
Anyway, there is a work around or two.
One method is to duplicate the last keyframe in your animation.
In your animation timeline leave a 100 ms between your last 2 (identical) keyframes.
Then in C3 call your next animation 50ms before the end of the next animation.
For example, use a fall animation called "Fall" 500ms long. Call your next animation, lets say "Falling_Loop", when "Fall" is at 450ms then call "Falling_Loop". ("Falling _Loop" can just be the same as the last frame of Fall for continuity.) That will avoid the last frame and the potential last frame jank that is happening with Spriter in C3 v-synced.