Virtual Bone effect is lost after re-importing mesh

After setting up a Virtual Bone on the skeleton and having it drive a Skeletal Control Node in an Animation Blueprint. Reimporting the skeletal mesh will cause the setup in the Anim BP to revert back to its default setup.

This was reported and tested in 4.21.1 (CL-4613538). This was reproduced in 4.20.3 (CL-4369336) and Main 4.22 (CL-4670176)

• Open the UE4 Editor and create a new Third Person template project
• Open the UE4_Mannequin_Skeleton and add a Virtual Bone to it
• Open the ThirdPerson_AnimBP and use the virtual bone to drive a Skeletal Control Node in any way or replicate the setup in the attached Blueprint
• Reimport SK_Mannequin

Results: The skeletal mesh in the Anim BP reverts to its default position

Expected: The skeletal mesh in the Anim BP doesn't change after reimport