problem with Navigation system

Hello everyone, i am making a game and i would like some help with the navigatino system. i have to enemy who is supposed to “chase” me but when i go near the stairs or on the stairs the navigation system seems to go crazy. to give you a bit more info i have 2 staircases, when i go to the 1st staircase the ai chooses to go from the 2nd and when i use the 2nd the ai chooses to go from the 1st

i uploaded a screenshot and a video for the behaviour