Here is the September schedule. On the Port Authority FB page, there is a comment on this image that states "Per request from our International Ferry Operators the passenger ferry schedule between the British Virgin Islands and the US Virgin Islands has been adjusted for the period starting 17th August until 15th October 2021 due to reduced bookings" so I assume this means this schedule is valid until 10/15. Not 100% sure about Sundays but logically, 10/3 should be Native Son and 10/10 should be RTFF. But that's the logical answer so I'm probably wrong... Call the carriers or book online to be sure!