After reading a few threads the solution that worked for me was turning on “Support Compute Skin Cache” and setting “Default Skin Cache Behavior” to “Exclusive” on the project settings. After that go to your skeletal mesh, on LOD 0 under sections, choose the model sections affected by the morphs and change “Recompute Tangents” to All.
This will fix both the normals and the seams seen below.
