When you say auto navmesh, do you mean auto generate worldspace? cuz iv been using generate > recast-based generation and i just found that when i ctrl click all the pieces for just one of the rooms at a time generate then do the next room it works but im only clicking the castle parts, you know like caslgrmwall01,caslgrmcorin01,caslgrmmid01 etc and im doing it from top down view.