Hi
Sorry for the late answer.
Aha. I was confused by the other graph you had. In this graph it seems you are purely using tags to control which nodes are traversable or not.
Unfortunately in this case the pathfinding scripts cannot prevent that connection. It sees that there is a connection (it has to be there because some agents may be able to traverse all tags) and it sees that both the source node’s tag and the destination node’s tag are both traversable.
When making the nodes completely unwalkable it can do some pre-processing on th connections to check adjacent nodes as well.
Would it be possible for you to use regular walkability instead of changing the tags of the nodes?