I cant see any pokemons in the nearby box [duplicate]

I have seen pictures of people having pokemon everywhere and having their nearby box full of pokemon and footprints but I have never had a single one no matter how far I walk.

I walked around 3,5 kilometers yesterday without getting anything in my nearby box and I never see the grass that sometimes should fly up from the ground.

I think that this is a bug or something because the ring that indicates when a new pokemon is added to the list pops up for me but for some reason I cant see the pokemon and the footprints so I can like only find pokemons when I use an incense.

I play on a samsung galaxy s6