Sailor Moon Season 2 Episode 13 moved to bottom of Season, described as “Unknown”

A weird thing has occurred. Sailor Moon Season 2 Episode 13 is still registered as S2.13, but when viewing the Season 2 timeline it resides at the very bottom, with the designated year above it reading “Unknown”. It was fine yesterday (I know because I’m currently watching the show), but I guess someone edited something and it is now misplaced? 

I don’t know what I would change in the Edit Page section to fix this. Can someone do so, and maybe share what was done for future reference if I see a similar thing happen? Thanks!

https://www.imdb.com/title/tt0526387/?ref_=ext_shr_lnk