NextJS 13 – 404 This page could not be found

I’m using the last version of nextJS (13.3) and have a fairly simple routing as follows.

- app
-- blog
--- [post]

The following route works perfectly in the local environment: http://localhost:3000/blog/just-a-blog-post.
But deploying on Vercel gives me the following error: This page could not be found.
the build to Vercel was successful, the home page works fine.