@sinkias If following the bone works as desired until you switch to another animation (the attack animation), it sounds like your new animation inside the Spine project might be keying other bone values and overriding your bone positions or set transform constraint mix values differently. Are you referring to the Spineboy example project, or are you using your own custom skeleton project? If you're using Spineboy, which animation is causing troubles for you? Could you show which code you're using the set the bone position, or are you tinkering with the example scene Spine Examples/Getting Started/4 Object Oriented Sample?
Since Misaki mentioned the BoneFollower component: I'm not sure what exactly you want to achieve, but if you want to override a bone's location to be at e.g. the mouse cursor position, BoneFollower is not an option. BoneFollower lets a GameObject follow a bone, while you likely need a bone following a GameObject or a custom position.
