Note: As already said, this loading appear even when the app/layout.tsx is loading. This is not the behaviour I want. In fact the behaviour I wanted is impossible to be needed with Next.js and his "SSR first" approach.
Note: I checked in React DevTool that the Suspend and the fallback is present, but the skeleton of the page is already rendered into the server so that Suspend is impossible to trigger!
You can see it as it is during long load, o I will probably remove it in the next commit.