When including a .PDF, caption is not below .PDF when using /eject page-height change

Consider the following MWE (you will need a test.pdf image to compile this).

This should compile using standard LaTeX. The problem is

• the caption is not below the .PDF image at all. It is on the next page.

• there is an extra page inserted before the image .PDF.

  documentclass[]{memoir}
  
  usepackage{graphicx}
  usepackage{caption}
  
  usepackage{epstopdf}
  epstopdfDeclareGraphicsRule{.pdf}{png}{.png}{convert #1 OutputFile}
  AppendGraphicsExtensions{.pdf}
  
  begin{document}
  
  eject pdfpagewidth=8.27in pdfpageheight=21.5in
  
  section{Vision}
  
  begin{center}
  includegraphics[width=0.9textwidth]{test.pdf}
  captionof{figure}{Caption.}
  end{center}
  
  eject pdfpagewidth=8.27in pdfpageheight=11.69in
  
  end{document}
  

  Please note that none of this weird behavior happens when using the following code (.PDF is here replaced by a dummy non-.PDF image):

  documentclass[]{memoir}
  
  usepackage{graphicx}
  usepackage{duckuments} 
  usepackage{caption}
  
  begin{document}
  
  eject pdfpagewidth=8.27in pdfpageheight=21.5in
  
  section{Vision}
  
  begin{center}
  includegraphics[width=3cm]{example-image-duck}
  captionof{figure}{Caption.}
  end{center}
  
  eject pdfpagewidth=8.27in pdfpageheight=11.69in
  
  end{document}