Please read this article: "Why can't I delete this trail?"
https://wiki.openstreetmap.org/wiki/Why_can%27t_I_delete_this_trail%3F

The OpenStreetMap database has tagged this path as a private access and private ownership. So, it is Komoot fault's to permit routing access in their app. Also, if it is the case, the user who added the track to Komoot is responsible because of going through a private property and sharing it.