There are following errors in the routing. When I want to plan from Norway with the Larvik - Hirtshals ferry, then I am constantly sent via Kristiansund. The same applies when planning via Langesund - Hirtshals.
For both ferry lines, the route is only given from Hirtshals, but not from Larvik or from langesund to Hirtshals.
Furthermore, many routes are shown as potentially closed, although they are only closed seasonally in the winter months.
If a connection is not right, especially with ferries, this can have many reasons. Use then for this section, if it must be, the straight line.
What is wrong now, if there is a note that the route is seasonally closed? It is displayed from when to when, if you click on the one-way sign.
Thank a lot for letting us know. There seems to be an issue with the road data. @linux-user fixed a few issues already a few hours ago, thanks a lot for this 
. I just fixed the ferry Hirtshals - Langesund, there hasn’t been access information for the ferry itself. I hope this works correctly in two days. If it does not work, please let us know.
In the meantime, you can use the beeline feature as Kurviger Tourer / Kurviger Pro user to plan the ferry with beeline.