Nikon 50mm f1.4, front focusing on my camera body

Nikon gives guidance on what you can cause poor focus accuracy in all camera instruction books.

The guidance mentions detail too small for the autofocus to detect in the viewfinder rectangle area - which is exactly what you have

Sorry but your test proves nothing, though you will probably got good results if you re test with a good target

--
Leonard Shepherd
Many problems turn out to be a lack of intimate knowledge of complex modern camera equipment.