If I understand your setup correctly, you want the first page of every chapter-level unit, whether numbered or unnumbered, to have no page number at all -- neither at the bottom center of a page nor in the header line.
You haven't indicated how you've achieved this look for the other chapter-level units, but one way of achieving this look globally, i.e., for the entire document, would be to insert the instructions
in the preamble. These instructions "let" the
plain page style (which prints a page number centered at the bottom of the page) to the
empty page style. I think you can guess what the main characteristic of the
empty page style is...