Animation events are not fired if the animation asset is not loaded during the preload phase.
Toggle Preload checkbox of _Anim.glb. If toggled on
[END] will get printed to the console. If toggled off nothing will get printed.
Another thing i noticed: In the docs it states that the time parameter of an animation event has to be normalized time. This is not true. The value of the time paramter has to be in seconds.