Seems there is a problem when rendering the styles in Nextjs using Griffel css-in-js engine. In the first build and run the styles are compiled and applied correctly, but when the page is refreshed, styles disappear.
So far the only recovery from this state is rebooting the app again (not good). This is behavior is observed during the development process. One possible workaround to solve this is described in the "The Perils of Rehydration" by Josh Comeau. Other potential solution is to follow the recommendations of Tim Neutkens in the following issue.