There are reports of bad routes on certain specific roads, like bridges and dikes, especially in the Netherlands. The reason is that some barriers were incorrectly added by mappers to the OpenStreetMap data. The routing software that is used by our optimization algorithm does not create routes through barriers by default.
The maps have been corrected by the OpenStreetMap community and we’re loading the corrected maps. That will however take a few days. The workaround is to change Options > Routing > Type of vehicle to the custom Deliveryvan profile, which has access to more roads and routes through some barriers.