When selecting animations in the content browser to retarget, the right clicking and selection "Retarget Animations". The selected items do not become selected in the RetargetAnimAssetsWindow.
Outcome: Animation Retarget window has no animations selected
Expected: Animation Retarget window has selected animation assets selected
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-226431 in the post.