Metahuman Facial Animation Issue

I’ve been researching some ways to reduce the file sizes of metahumans, So far the best option seems to be reimporting the face file, a few material slots are lost but apart from that there’s only one major issue. When testing the animation skinning test that comes with metahumans, the new face doesn’t move at all despite using the exact same skeleton. You can see that the morph targets are activating on the face but it’s not animating fully.

Am I missing something like having to retarget?