Some shippers from China consolidate multiple items into a single bulk shipment when sending goods to America. The shipment is declared as one entity for customs purposes, and taxes and duties are paid based on the declared value. Often, the declared value is intentionally set lower to reduce the amount of tax and duty owed, which most people already know.
Once the bulk shipment arrives in America, it is handed over to a local shipping agent, who then arranges the final delivery of individual items.
This method is commonly used to manage, minimize, or avoid higher taxes on shipments by under-declaring values and consolidating multiple packages into one, taking advantage of how customs processes bulk imports, likely why some of the American packages are getting through unaffected.