@Telosma Which exact version of the spine-unity runtime (name of the unitypackage, also in Assets/Spine/version.txt or version in the Package Manager) are you using?
Could you please describe in more detail how exactly (in code or settings) you are modifying the animation speed to make it slower?
Also, do you mean that the GameObject's Transform movement is not applied equally to the physics constraints in the skeleton, or that the animation itself played back slowly does not trigger the same physics constraint behaviour?
Could you perhaps share a minimal Unity project which still shows this issue? You can send it as a zip file to contact@esotericsoftware.com, briefly mentioning this forum thread URL so that we know the context. Then we can have a look at it.
