Healthbar / Progressbar not updating

I plugged a print string inbetween the Cast and Set Percent, and nothing happend. When I plugged it into Cast Failed it printed.

So I guess the cast doesnt work. However, I dont see why. I made a exact set-up for the enemy and its health bar, and it works just fine! So something has to be wrong with that exact cast (“Cast to W_HUD” on main character).

any suggestions?