The ordering is by release date but if you go down to 27x05 it’s appearing after the 3 before it when it should be before. Same issue with 27x09.
Adjusting the ranks with the default sort being Release Date does not fix it. I change 27x05 to Rank 23 and it remains in place. These two actions, adjusting ranks and sorting by release date, don’t seem to work well together.