Visits from French Guiana in South America are incorrectly tagged as being from France in Europe. The visitor map filter for South America displays them on the map, but hovering or clicking indicates they are France, not French Guiana.
this might be an issue of the way how GeoLocation works. If you have visitor from French Guiana, and one cannot be identified by IP through your configured GeoIP provider, then browser language is used as failover to identify nationality/location of the visitor. Please feel free to post improvement request on GitHub, but I’m afraid there is no way around this except for you using GeoIP database which will provide needed data.