Visiting China for 2 nights

We are from the UK and departing on a Royal Caribbean cruise in May from Singapore visiting Vietnam and Hong Kong and after 9 days at sea disembark in Shanghai but then stay over for 2 nights in a hotel in Shanghai. We then depart back to the UK (Manchester) via Dubai Airport. We are receiving conflicting information of whether we qualify for the 144 hour exemption. Can someone please advise as soon as possible.