Seems the problem was my path to $"SunAnim". I needed to make it $"Sun/SunAnim" so it would navigate to the animation player.
Though it doesn't seem to keep track of the player's x coordinate at all.
Upon testing, it keeps only one x value: 0.219436. I want to know its location within the level (local x), but not even declaring it in delta works.
EDIT: I had to remove the mesh's name from the path and refer strictly to the kinematic body in order for it to keep track of it all the time.