Table of Contents showing in original language

[d5364t54ytfr4]

I was trying to translate a Japanese eBook to English and noticed the TOC is not translated and still in Japanese.

The TOC doesn't seem to be translated into target language.

And then there is this bug with Sumatra Reader that only happens in the translated file and not the original file may be related to this. https://github.com/quantrancse/epub-translator/issues/3#issuecomment-1415242418

Edit: Android Readers like https://github.com/voice and Evie say that the ePub is damaged.

Edit: Converting the generated ePub to Mobi and then reconverting it back to ePub solves the problem for me.