Why is NPC is moving to a certain place only once?

I made this script so that an NPC will move to different waypoints multiple times. However, it only moves there once. Any ideas why it isn't working?

SCRIPT:

local waypoints = { game.Workspace.WayPoint, game.Workspace.WayPointb, game.Workspace.WayPointc, game.Workspace.WayPointd, game.Workspace.WayPointe, game.Workspace.WayPointf }

local chosenWaypoint = waypoints[math.random(1,#waypoints)]

local humanoid = script.Parent.Humanoid

local pos = chosenWaypoint.Position

while true do

wait(1.5)
humanoid:MoveTo(chosenWaypoint.Position)

humanoid.MoveToFinished:Wait()
wait(1.5)
humanoid:MoveTo(chosenWaypoint.Position)

humanoid.MoveToFinished:Wait()

end