144 TV and flight route

We are travelling to Shanghai tomorrow and will be staying until Tuesday, when we leave for Singapore. We will be staying in Singapore until Thursday. Our return flight to the US however routes back through Shanghai.It technically meets the A(Los Angeles) to B(Shanghai) and B (Shanghai) to C (Singapore) requirement for the 144 TV. When we show up in Shanghai on Thursday in transit back to Los Angeles, would we be reset to A->B, B->C?

Does this make sense?
Or here;

April 12th Los Angeles -> Shanghai
April 16th Shanghai -> Singapore
April 18th Singapore -> Shanghai -> Los Angeles (5 hour layover)

PS: This was a reconstructed trip as I didnt understand it was to a 3rd nation and had a LAX->PVG round trip ticket... and we didnt get on the plane due to my misunderstanding. Just trying to make sure I get this right.

Thank you in advance