loader in valuebox shiny

I use the shinycssloaders package for spinners on charts, and it works fine, but not on valueboxes

I would like to put spinners in each valuebox while the data is displayed, like on this example

image

here is the code where I tried to do it

box(
        title = "mon titre", status = "warning",collapsible = TRUE,width=4,
        withSpinner(valueBoxOutput(ns("a"),width=6),type=4),
        valueBoxOutput(ns("b"),width=6),
        valueBoxOutput(ns("c"),width=6),
        valueBoxOutput(ns("d"),width=6)
      ),

I have the impression that the spinner is positioned on the box and not on the valuebox

thanks for your help

like this
image