title: Grouped rows (rowspan>1) on multiple pages lose background color @media print (only on Firefox)
body: <p>Printing a simple table with grouped rows (within a color) across multiple pages does not render correctly.</p>
  <p>When a grouped row has a background color, it is lost on the other pages in Firefox.</p>
  <p>You can find a sample code below.</p>
  <p><a href="https://i.stack.imgur.com/yA2mA.png" rel="nofollow noreferrer">screen capture of a pdf file with the problem</a></p>
  <p>I have report the <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1768610" rel="nofollow noreferrer">bug</a> in bugzilla. Any workaround ?</p>
  <p>Thank you !</p>