Metadata TVShow

Hi all! Infuse in the best app to watch videos on iphone or ipad but i have a question.
Now i can see the poster of the tv show:
Directory Arrow
Sub dir: Season 1
Inside all the files.
Everything right and i can see the poster of arrow in the main dir
Directory The Flash
sub dir Season 1
Inside the fils
In that case i can’t see the poster but a generic dir image.
Why sometimes i see the poster and sometimes not?

This seems to be part of the same issue I reported here: