To reproduce the hydration error just set the view to home then scroll down and you’ll see the observer is broken. Then refresh the page and voila this error appears: Unhandled Runtime Error Error: Text content does not match server-rendered HTML. See more info here: [https://nextjs.org/docs/messages/react-hydration-error](https://nextjs.org/docs/messages/react-hydration-error "smartCard-inline") To fix it you have to clear the filter-mode-type cookie and it is good to go.