Thank you, that lead me in a direction which worked for me.
For anyone else maybe sitting with this type of issue. I used “Get closest point on collision” of my target (which was the wall). This allows my enemy to move towards this location with the nav mesh still being affected by the wall actor.
As seen here, the trace is done (the yellow sphere). My enemy moves towards it and attacks successfully with my friendly AI now taking alternative routes towards the enemy, instead of trying to move through the wall.
Much appreciated.