Why does the application work crookedly after building Webpack?

Question

React

I'm making a React application, using the "react-beatiful-dnd" library, everything works fine before building the application:

But after building, some nonsense happens with D'n'D:

Maybe someone knows what the problem is?
Link to the assembled application: https://taskboard408.000webhostapp.com/
Link to the github repository: https://github.com/alexanderklychkov/taskboard