The resetServerContext function should be used when server side rendering (SSR). It ensures context state does not persist across multiple renders on the server which would result in client/server markup mismatches after multiple requests are rendered on the server.
Use it before calling the server side render method:
import { resetServerContext } from 'react-beautiful-dnd';
import { renderToString } from 'react-dom/server';
// ...
resetServerContext();
renderToString(...);