MTM installed but dashboard not showing visits

I have correctly installed the MTM in my React webapp in the dev environment. Just for testing purposes, I am using the same MTM (configuration, tags, triggers and variables) of another working website so I am pretty sure the overall settings are already ok.
I then installed the @datapunt/matomo-tracker-react as stated in the documentation
I wrapped the App with the MatomoProvider and visited the app. After the first logging, however, the visits have no longer been registered.

What might be happening?