Adding Nav Modifier as a component in Actor and via "add component by class" leads to a different result

Here is what it looks like when I add a Nav Modifier in the Actor BP:
And this is how it looks when I add it at runtime via “add component by class”:

Is this supposed to be like this or is this maybe even a bug? I didn’t find any way to change the size or the local position (it is not only to big but also has the origin at 0,0,0 of the Actor) after adding it.
Any way to circumvent this behavior?

Edit: This shows the issue even better. The modifier isn’t using the Actors Mesh to define the size of it.

So Nav Modifier Component is just broken and does whatever it wants.
However, while browsing the web, I found another solution. Instead, use a normal Collision Box and check the Dynamic Obstacle box. This turns the Collision Box into a Nav Modifier with all the options that a Collision Box provides.