OK that explains your issue. It shows you the next available time slot for an attraction but then takes into account what you already have for LLMP selections around that time. It will not let you have very large overlaps of earlier LLMP selections or Dining reservations.At DAK for Wednesday 8/28 currently have KS 8:25-9:25 and NRJ 9:25-10:25. Originally had FOTLK for 11AM show but was able to change it to 10AM show, and then was offered NRJ at 10AM but nothing earlier.
Some Guests have reported being able modify to have more attraction overlap while in the park. MDE really want's of offer you times after the current time window of about a minimum of 1 hour between return windows.
ETA: add MDE information to second paragraph.
Dave