MG 2.2 Re-mirror image from restored post?

[lg19]

Hello. This is what happened -

1. User inserted image into their post
2. Image was mirrored in MG
3. Moderator deleted the post
4. Moderator restored the post
5. I rebuilt the “XFMG: Sync attachment media mirroring” cache
6. Image is no longer mirrored in MG

Have I missed the correct way to restore the mirrored image? Thanks!