Hi, UK citizen going London-HK-Shanghai-London but not direct from shanghai to London

I understand that I would qualify for the 144hr exemption in Shanghai as I am coming from HK and going to London (3rd country). However, my flight back to London would connect back at HK for 2 hours, so does going to the 3rd country have to be a direct flight to qualify for the exemption or can it still connect at your first country/region (provided you stay airside at the connecting airport)?