TWOV Eligibility

Hi
We both have full British Passports
We enter China JNB-HKG-PVG on Cathay Pacific
We stay 2 nights in Shanghai
We depart on Costa Cruise within the 144hr limit with first destination as Naha( Japan)
The cruise docks again later in Hong Kong but ALSO in Sanya (PRC)
Does the fact that we visit Sanya prevent us from making use of the 144hr TWOV in Shanghai

Thanks

Tony