Sorry to hear you're having troubles.
Lladruc The problem is when re-importing to Unity. The animation re-imported is animated but what I see is (I think) the various frames but shifted the image or something.
If you exported your skeleton data as .json or binary, you don't get individual frames exported as images but instead atlas textures that contain all your attachments, in packed form to take up less space. These atlas textures are then applied to the skeleton mesh, which is animated at runtime in Unity by the SkeletonGraphic component.
If textures are offset, it sounds as if the .atlas.txt file does not match the texture .png file. Are you sure that you have copied both files over from the export directory to the Unity project directory? If so, please check whether perhaps you have accidentally exported the newer file as .atlas instead of .atlas.txt file, which would then be ignored.
If that does not resolve your issue, it might be the easiest way to open the respective directory in your file explorer and delete the old exported skeleton asset files (.json, .atlas.txt and .png files, don't delete the other files if you want to keep existing scenes working) before copying the newly exported assets over. Then after the files have been copied, you can switch to Unity to have everything imported.
Also see the documentation section here:
https://esotericsoftware.com/spine-unity#Updating-Spine-Assets
