In my game, one of the mechanics is for the character to be able to build walls and turrets to defend himself from the horde.However, the AI always chooses to always try and traverse the wall, therefore, getting stuck and not being able to move. What I really hope for it to do is to instead look for a different route to the player. Is there a possible way, besides making an updating NavMesh, to be able to fix this? Thanks in advance.
This solution may slow your performance down quite a bit depending on how many AI controlled objects you have, but you could use Physics.RayCast to check if there is a collider in front of the object, and if there is, rotate object until there is not one before having it continue along its path. I do not suggest this method, however, as it could lead to a lot of issues performance wise as well as the chance of it not working at all.
Here is a link to the navigation and pathfinding page of the manual.