Anyone know this artsie thriller from around 2016?

I only remember some key points. A person moves into a building in a city street and spies on a person across the street. There is a jar with black fluid or slime that bubbles sometimes and the camera focusses on it very often during the whole movie. Also there are flashbacks of black rocks and stone poles in the sea or a cliff where the waves crash upon. I know it’s vague but the jar thing should help out maybe.