SOLVED!
I do not understand why, but while Autodesk Motion Builder 2019 is a fantastic program, I do not understand the error of retargeter any G8, (And the G3 ...), for, apart from its "special" bones, the bones of its face are a problem for a retarget. NOT "inside" Motion Bulider, which can exploit FBX for Daz without much problem ... But, if we want to export an animation in BVH, we must remove "All" facial animation "bones". In Mobu it will look horrible, but in Daz it works perfectly.