A3 PDF prints first page correctly then reverts to A4 paper for the second and subsequent pages

Am trying to print an A3 PDF from my Macbook Air running Sonoma 14.4.1.  Using a HP OfficeJet Pro 7730 printer.  The first page will print out fine  (albiet very slowly) on A3 paper however it will then revert to A4 paper for the 2nd and subsequent pages.  Is there a setting or something I'm missing?  Have trawled through them but once I've selected A3 there isn't any other options for stating all pages or anything .