Implementing AI navigation in blueprint class

So i am making an endless runner and in this endless runner i decided to make enemies. I want the enemies to keep following the player so i added the ai moveto event. the problem arises when i need to put the nav mesh into the world. this is because i am spawning the floor using a blueprint class. when i put the nav mesh in the blueprint class it’s invisible and uneditable:

this is the floor that i am continuously spawning and where i wanted to place my nav mesh but im not able to

does anybody know how i can do this or another way around it?