Navmesh Help

Hi, I have a problem while baking my navmesh, there is this piece of
navmesh that bakes with my plane and I have no idea why it is there and where it comes from (The Purple rectangle aboce the map, it also cuts off the navmesh at the bottom for some reason).

Not only can I not get rid of it by deleting everythi
ng from my hierarchy and rebaking but when I make new scenes and bake, it is still there (New Scene, only navmesh there is the purple rectangle...still).

I've been running in circles trying to get rid of it and i've come up with nothing, does anyone have any clue what it is or how I can get rid of it?
Thank you.

 

What do you see if you click on the Areas button toward the top the Navigation tab? I think the different color of that purple region indicates the region is a different Area type. I'm still not sure why it would persist after removing all game objects from your scene... You're saying this thing exists in a brand new scene?

 

It was a custom area I made but no longer use on any objects (It is User 3). Yes it still exists in a brand new scene, and every new scene I make, thinking about redoing the whole project and just exporting and re-importing everything into the new project.