Kindles NEVER open on the Title page. This is the way the Knindle is designed to work and the only people who could change it are Amazon. if you want to see the title page then you ahve to get to it via the Table of Contents.
However why they should not show up in the Calibre reader is a bit more of a mystery? Have you tried setting the cover images at the Calibre metadata level prior to conversion? It is possible that you have your conversion settings set to remove the first image found which is why it is disappearing - this is not at all an uncommon thing to do if you want to sue the cover image set at the Calibre metadata level.