I had this happen and I had paid for the old WiFi package that didn’t work and struggled to get ADRs and then I was showing someone how I couldn’t get it to work and had forgotten to sign into the paid WiFi and was was just using the ship WiFi for the navigator and the Disney app worked to book ADRs I think because they are on the same Disney IT platform and aren’t filtered out. So try the regular disney app to see if it works while at sea before buying the internet package. We have purchased the internet package now that they have the new starlink system and it works great. We buy the unlimited for one device and share the login across our families devices at different times. My husband has a crazy long streak on duolingo and he doesn’t want to lose it while cruising.