[conanite]

The Place Charles de Gaulle Étoile (Arc de Triomphe) in Paris is a gigantic roundabout, with the peculiar feature that traffic entering the system has priority ; traffic already on the roundabout must yield. This would lead to perpetual gridlock were there no traffic lights controlling access to the roundabout. This kind of junction used to be common in cities.

Out in the countryside roundabouts in France operate in the "normal" way : approaching traffic yields to traffic already in the system, with the usual triangular "yield" sign making priority clear.

It's possible that your experience of French roundabouts is related to driver confusion between these two systems.