The bug

When changing the render distance from e.g. 16 to 5 and then moving around will leave a "player chunk load entry" at the position. This means the chunks at this position stay loaded in the size of the render distance of the server.

The behaviour can be seen in this video: https://www.youtube.com/watch?v=yw-BxLLd2PM&feature=youtu.be&t=268