It’s been years since I had to make a print version of a webpage and support for page-break-before and page-break-after in Chrome seems to have improved in the mean time–even if I’m really supposed to switch to break-after (support for that seems to be lacking in Chrome, Edge, Safari and Internet Explorer).
I knew floats could cripple page breaks but I wasn’t using any floats so I wasn’t sure why it wasn’t working…