How come my pathfinding npc script is so laggy and stuttering?

so ive been working on this all day and basically my npc stutters or lags when it moves. it like freezes for a half a second pretty often

its supposed to follow the player even when they move

local function getpathfindingpath(entity, nearestplr)
    local entityPath = pathFindingService:FindPathAsync(entity.PrimaryPart.Position, nearestplr.PrimaryPart.Position)
    local waypoints = entityPath:GetWaypoints()
    return waypoints[2]
end

wait(5)
local function getwaypoints(v)
    local nearestplr = game.Players:WaitForChild('thenormalelevator3').Character  
    local waypoint = getpathfindingpath(v, nearestplr)
    return {waypoint, nearestplr}
end
for q,w in pairs(entity:GetChildren()) do
    if w:IsA('BasePart') then
        w:SetNetworkOwner(nil)
    end
end

runservice.Heartbeat:Connect(function()
local waypoints = getwaypoints(entity)
    local v = waypoints[1]
    if v ~= nil then
        local pos = v.Position
        entity.Humanoid:MoveTo(pos)

    end

    end)

here's my code