Hello Tasty, thanks a lot for the feedback, can I get a further information about the issue “the navmesh not allowing them to go through areas they should be able to go through”? Are you hitting this issue by importing custom assets or using Fortnite props? It is very likely the navmesh generated in the area is not considered as a navigatable space for the AIs, but they shouldn’t move through a wall as well. The AIs would only navigate through a wall when you enable the Environment Damage setting in the Island Setting, so the AIs would break the walls and navigate through.
The navmesh changes in UEFN can only be done through the props which impacts navmesh or device like AI Navigation Modification.