Why can some ships cross the Strait of Hormuz during the "lockdown" period?

Why do some ships cross the Strait of Hormuz during the blockade period? CNN reports that there are two key points: first, this blockade covers all Iranian portsboth those located inside and outside the Strait of Hormuz, but it does not include the strait itself. Ships not related to Iran can pass through. According to international maritime law, blocking international waterways is illegal. Second, during the blockade, the US military can intercept ships carrying goods related to Iran thousands of miles away. Even if a commercial ship has already left the Strait of Hormuz, as long as it is in international waters, it may still be a target for strikes. According to CNN, Bjorn Hojgaard, CEO of the ship management company Anglo-Eastern, stated, "Pay attention, don't interpret the blockade literally as a physical interception on the strait." Meanwhile, the US Central Command stated that they have deployed over a dozen warships, more than a hundred aircraft, and over 10,000 personnel to carry out the blockade task. Former US Navy captain Carl Schuster stated that most of the US military's forces are operating outside the Strait of Hormuz and the Iranian coastline. According to Reuters, a source familiar with Tehran's side of the story revealed that as part of negotiations with the US, Iran may consider allowing ships to freely navigate the Omani side of the Strait of Hormuz without fear of attack, provided that an agreement to avoid conflict escalation is reached.