The Romanian government has approved a new list of countries with high epidemiological risk, and based on it there are some countries that make the transition from the yellow zone to the red zone, so quarantine is imposed for all Romanians who are not vaccinated, regardless of whether they have an RT-PCR test negative or not.
The Romanian government updates these lists quite often, so that Romanians who go on vacation abroad during this period risk being unable to return home without being quarantined, which is a problem for many.