How to create prototyping animations from within the editor

I need to create some placeholder animations for prototyping (trying to add melee attacks in my game). I only need to rotate some bones and be able to access it as an animation sequence.

After some research I found [this tutorial](Editing Animation Layers | Unreal Engine Documentation on editing animation layers, but it doesn’t seem to work. I copied one of the default animations and modified it this way, and it looks fine in the animation editor, but when I actually play the animation sequence in my anim blueprint, it stays at the first frame, even though the animation has 8 seconds of frames and should continue playing. The animation is playing in my blueprint, at the correct speed and for the correct duration, but the skeleton doesn’t move past the first frame.

I also tried to create an anim montage from it and the montage is stuck at the first frame too. Is this tutorial outdated? I feel like something doesn’t work.

So my question is simply: How can I just take my skeletal mesh and make new animations for it as a prototyping system that can be quickly edited?

Screenshot of my current animation joined, in case anyone can see what I’m doing wrong

I can even see the animation playing and I can move its frames etc, but the mesh doesn’t move at all.

231554-frames.png