I have created characters and rigged them using Mixamo and then added a control rig via the Mixamo Blender addon. All good so far. I then download Mixamo fbx animations and push them down in the Action Editor for one of my own characters. They now appear in the actions list in the NLA. Sometimes they work but most times they just switch the character pose to the rest pose. I've switch from hold to nothing, tried replace, combine, add, multiply, no effect. I've unchecked and rechecked the actions, no effect. When it does work, the actions mildy warp the main character. I have been playing with this for days and have run out of ideas.
I'm using Blender 3.4.1, windows 10.