Yeah I see that too. Weird.
I guess with park ressies, it kind of makes sense. Onsite guests get priority, so it will prevent folks from booking 3 nights on site, buying 10 day tix, and then being able to book the other 7 from the tix associated with their onsite? It will also force folks to buy new tix (more spenny than adding days) if they are going offsite. Win win for Disney
But man that is rough, particularly for split stays.
And for those who are only just now booking vs those who booked before that change.
Hoping others will chime in to share this as their experience too, and that someone somewhere will find a workaround?