You’re welcome, and thanks for posting the video. Since the morph targets are working on your character’s head mesh earlier in the video, it seems to be a bug when the morph targets are not working later. In other words, your head mesh is probably fine. Just remember, the PREVIEW mesh is not actually the final mesh. You will need to assign the correct skeletal mesh in your character’s Blueprint. To be honest, prior to watching your video, I myself had not been able to get any morph target animations showing, so you were already doing better than me there. 
However, this post might help. The main facial movements are controlled by bones, not by morph targets. All Morph Targets are only used at LOD 0, and fewer morph targets are used at other LODs. You can see this effect by changing from LOD Auto to other LODs while the morph targets are set to 1. Metahuman facemesh morph target preview not working?
