You wrote that you “can swap animations between the two, but not the mesh.” Try:
- Open an AnimSequence
- Select the “Mesh” tab at the top
- Select “Preview” at the top
- In the “Mesh Details” panel, under “Mesh/Skeleton” select the Skeleton you have retargetted to.
- If you have followed the previous instructions from the video and the linked documentation, you will see the other skeletal mesh that you want to change to.
- Select this.
- Now all the animations will preview with the desired mesh