How to use Powershell to paste an excel table into powerpoint while keeping the formatting

I am trying to paste several excel tables into powerpoint using Powershell:

$shape = $slide.Shapes.PasteSpecial($ppPasteJPG,$false,$null,$null,$null,$null)

It seems to work perfectly with two of the 6 excel tables I am pasting, but with the other 4 it does not. The two it works with are .xlsm, whereas the 6 are xlsx. Why is this, and how can I make it work with all of them?