Why is the second debounce not working?

The first debounce works. Why is the second debounce not working? So the first debounce is so the NPC takes 25 damage every 0.5 second. The second debounce is suppose to wait 5 seconds before the player gets EXP because when the NPC is dead, and the part touched the NPC again while he is dead, it gives the player more EXP. Is there a way to give the player EXP once when he kills the NPC?

local debounce = false
local debounce2 = false
local player = game.Players.LocalPlayer

function onTouched(hit)
    if not debounce then
        debounce = true
        if hit.Parent.Name:sub(1,17) == "AFK Noob Lv 1 HP " then
            hit.Parent.Humanoid.Health = hit.Parent.Humanoid.Health - 25
            if not debounce2 then
                debounce2 = true
                if hit.Parent.Humanoid.Health == 0 then
                    player.leaderstats.EXP.Value = player.leaderstats.EXP.Value + 16
                    wait(5)
                    debounce2 = false
                end
            end
            wait(0.5)
            debounce = false
            elseif hit.Parent.Name:sub(1,4) == "Noob" then
            hit.Parent.Humanoid.Health = hit.Parent.Humanoid.Health - 25
            wait(0.5)
            debounce = false
        end
    end
end

script.Parent.Touched:connect(onTouched)