Ok, two thoughts based on a quick look. In the file itself I’m only seeing the baked reload animation and no baked equip animation. Is that correct or are all your actions baked in your file?

Can you also confirm that in your first video, the equip animation is set as the motion in the starting state of both the gun and the arms animation controller? It looks like it could just be gun controller not having anything assigned to the state, but I could be wrong.