Once Kanada closed their border, they invalidated the agreement. Giving a Kanadian driver the option of delivering to the United States, and not returning because they didn't take the Jim Jones Jab, voids any agreement.
In addition, any trade agreement between the United States government and the Kanadian government is null and void once either party is violating citizens' rights to enforce it.
Go back and get your facts straight.
The U.S. border restrictions were much more onerous than Canada’s.