AI Roaming after "losing" player?

I currently have a simple AI character that will randomly roam about the map until it sees a player and then it will follow them around. I would like to make the player be able to hide from (get out of vision) or get far enough away from the AI to “lose” it or get away from it, and when this happens, the AI will go back to roaming the map. Currently, the only way to get away from the AI is to go out of bounds of the Nav Mesh Bounds, and when that happens the AI just freezes in place. I have looked at a bunch of tutorials, but they all basically show what I currently have, which I’ll put a picture of below.

Any help would be greatly appreciated!