Maybe Chinese exporters are overstating their exports, in general and to the United States. Overstating exports is a classic way of getting capital into a country with capital controls.
Or, maybe US tariffs have created a strong incentive for firms importing into the United States to go to some lengths to understate their imports from China. Thus, U.S. imports from China are now likely under-counted (which by implication holds the bilateral trade deficit down).
https://www.zerohedge.com/markets/bizarre-discrepancy-emerges-trade-data-between-us-and-china
Econophysics2020 