Saving new FBX / OBJ, overwriting existing one in Unity3d scene, but new animations don't show up.

Newly imported file does not show new animations unity3d
Sometimes animations don't show up in after updating a file. They are present in the dropdown "Source Take" right under the list of all the clips.

You'll need to add the manually. Simply click the "+" sign under the list of clips, select your new animation as the source and configure it, then apply.