Keep checking, sometimes things load differently. Try too for specific times vs the ’meal’ option. Also try different party #. If you have 2 people try for 3 or 4. They like even numbers better than odd so always try rounding up if you are odd-so look for an adr for 4 for your party of 3.
If you need to book a prepay option for an inflated adr, make one member 2 yo. No charges and it’s a great workaround a dining cm gave me many years ago. We do what we need to work within the oddities of Disney dining. Good luck!