144 Hour Waiver or multiple entry visa?

Hi, We are travelling from the UK to Shanghai arriving at 15:30 on 21 July 2020 and spending 4 nights in a hotel before a back to back cruise on 25 July from Shanghai to Japan but which comes back to Shanghai on 02 August and departs again on the same day to Japan but comes back to Shanghai on 10 August. We fly back to the UK in the early hours (00:05) of 11 August 2020. I am not sure whether this would qualify for the 144 hours without a visa. By my calculations we have 4 days in Shanghai at the beginning, 1 day in the middle of the back to back cruise and then another day at the end as we fly out from Shanghai. This is 6 days which equates to 144 hours but I am concerned that this may be qualify as a 'multiple entry' rather than 144 hours. Do you have any advice?