My charater model have one set of deforming bones, and another set of target bones that is driving the deforming bones through constrains. I create the target bones by duplicating the deform bones,remove parents and weights, then adding IK constrain to the "hands" and "feet", then adding pole target bones for those IKs. My animation is done by keyframing only the target bones.
I created a run cycle, saved it as a RUN action by clicking on the shield icon in the Action Editor, then moved on to create a new IDLE action. On this IDLE action, I reset the target bones to the default T-pose, then add a keyframe to all of them, then save the action.
PROBLEM: When I go back to the RUN action, the run animation is broken, and stay broken even if I delete the IDLE action.
I have tried adding single keyframe to all the bones (including bones that stays still during the animation and pole target bones), my NLA timeline is empty, but the problem still persists.
I want to include multiple diferrent actions/animations in a single object, so I can export it to a single fbx to Unity later. I could try to break the animation to multiple blend files, but that would be a nightmare to import and manage all the animations inside Unity.