Please change the imdbId to (tt3615768) this was the first Japanese anime version but later it was merged with the English version, but there are applications (Kodi and Stremio) that use the old Id and don't show results for the Id in English.

https://community-imdb.sprinklr.com/conversations/data-issues-policy-discussions/the-merge-two-titles-does-not-work/5f4a799b8815453dba835109