I checked the location where you get stuck and it seems like webwalk must think that there is a route through that area, im in contact with the dev for that.
edit: we did some investigating and currently mirrormode for some reason tries to generate a path through an area that is not reachable, so this was send to the next dev who has access to change the webwalker code. As long as osbots mirrormode isnt updated I would suggest using the other swampcrabs area. I will mention you when its fixed @Fich420