Maduro is a corrupt dictator who holds sham elections, but that does not change the fact that he unfortunately is the president of the internationally recognized government. Will you also propose US seize Turkish or Russian freighters because Erdogan and Putin "won" elections under highly suspect circumstances?
If Putin came out in 2020 and said "I do not recognize Joe Biden as US president, he stole the election, Donald Trump was the real winner, so I am sanctioning America and seizing American LNG tankers" everyone would take that as a hostile action and even a casus belli.