Do I qualify for a visa- free transit- LHR-PEK-HKR then same in return

Hello

My husband and I are travelling from London to Beijing on the 26th December
We arrive the 27th December and will spend 4 days there before departing to Hong Kong on the 31st December

We repeat the journey on the 4th January- travelling from HKG to Beijing, have a 3 hour layover and then travel onto London.

My reading of the guidance is that we are eligible for the 144hrs free transit. We will be staying in the Beijing, Tianjin and Hebei areas, for less than 6 days, which should mean a visa isn't necessary. Have I interpreted this correctly?

Thanks
Claire