Can you confirm that my route arriving and departing from China qualifies for the 144 hour visa-free

Good day,

I will be in Mainland China (not including HongKong) for roughly 4 days. Can you confirm that my route arriving and departing from China qualifies for the 144 hour visa-free arrival policy?

We are United States citizens and are among the 53 countries listed as partners in this policy.

Wednesday, March 8:

Hanoi → Shenzen, China → Beijing Capital International Airport


Saturday, March 11:

Beijing Daxing International Airport → Xiamen ( Bandara Internasional Gaoqi T3 ) Overnight stay

Sunday, March 12:

Xiamen → Hong Kong International Airport