Thank you for the detailed report and for including your project file and videos!
Looking at what you're describing — the animation window and the Preview view showing different results — this is actually expected behavior in many cases, and here's why:
How the Animation view and Preview view work differently
The Animation view (dopesheet/graph) shows the animation keys exactly as you've authored them, applied on top of the setup pose. It shows only the currently active animation in isolation.
The Preview view, on the other hand, simulates runtime playback. It uses AnimationState to apply animations, which means it factors in things like:
- Mixing/crossfading between animations
- Multiple tracks playing simultaneously
- Alpha values on tracks
- The animation being applied on top of whatever was previously playing
So if you have a previous animation set on a track in the Preview view, the current animation may be blending with it, which can cause the result to look different from what you see in the Animation view.
Things to check in the Preview view
- Make sure only one animation is active on Track 0 and no other tracks are active, to see the animation in isolation.
- Click an animation button once to set it — if it was already set, click it again to clear it first, then set it again fresh.
- Right-click a track button to toggle the animation for that track.
- Check that additive blending is not enabled on any track, as that would also cause differences.
Regarding the update
It's worth noting that updating from an older version to 4.3.26 should not change how your keyframed animations are stored — the animation data itself is preserved. The Preview view may just be reflecting runtime blending behavior that you may not have noticed before.
If after checking all of the above the animations still look genuinely different (not a blending issue), it would help to describe specifically which bones or attachments look different between the two views. You can also try loading your .spine file in the Skeleton Viewer to check the exported animation data independently.
