Does Manga Have Fillers?

BUT WHY?

Yes, a manga can have fillers. 

Anything that brings no plot development and directly affects the main story can be considered a filler.

Mangakas employ the use of filler chapters to make their deadlines or to meet contractual demands.

ALSO...

Plot Development

When mangakas need to ponder what is next for their characters, they put fillers in to buy themselves more time.