Thanks for sharing your Site Health information @valdinia. From reviewing your site, I can see that there may be a WP Cerber block for that could potentially be impacting Analytics visits.
I can also see that your CookieLaw configuration may be impacting Analytics reporting, as per this screenshot from the checks I performed on your site.
From reviewing the screenshots you also shared, it looks like Site Kit is reporting what you’re seeing from analytics.google.com, and it’s more a case of you having lost traffic since around 15th August. Site Kit is displaying your traffic from the previous 28 days, and not only data from when your site was not reporting.
If you can temporarily deactivate your Cookie Consent plugin, along with WP Cerber, I can check your site once more and Analytics is reporting site visits as expected. This would indicate no issue with your Site Kit configuration, and more a consent management and/or security plugin configuration.
Let me know if you have any questions with the above.