Hey HavocX,
I’ve allowed sprites to influence nav mesh generation in /UnrealEngine/commit/af2da0c353e5431f432fc0cda60fbbfdfe32178d . You can probably work around it in 4.4 by creating a Blueprint from your sprite and setting bCanEverAffectNavigation property to true (it’s only editable on defaults of an object, not on an instance, hence need for a BP).
Cheers,