I can confirm you cannot do a back to back to United States when the ships destination is Puerto Rico. I tried when the Wonder departed Gavelston and finished in Puerto Rico. Figured I’d then take it for 3 days to Port Canaveral. Booked trip on phone and they actually booked me on both cruises. A short time later I received a call from same person who said she’d have to remove one of the cruises. I kept the one way to San Juan. Spent a few more days in Puerto Rico and then flew home.
Disney ships are technically not ships from the USA. They are Bahamian.
From Wikipedia.
“The Jones Act prevents foreign-flagged ships from carrying cargo between the US mainland and certain noncontiguous parts of the US, such as
Puerto Rico,
Hawaii,
Alaska, and
Guam.
[13] Foreign ships inbound with goods cannot stop at any of these four locations, offload goods, load mainland-bound goods, and continue to US mainland ports, although ships can offload cargo and proceed to the US mainland without picking up any additional cargo intended for delivery to another US location. Usually, they proceed directly to US mainland ports, where distributors break bulk and then send goods to US places off the mainland by US-flagged ships.
[13]”