DefaultEcs: Entity.Set Slowdown Monogame FPS

Hello,

i have trouble to find the solutions for the following Problem: If i add this Line of Code my Fps go from 3000 to 60 in Monogame tiles[tile + j].Set<Show>(); I have 3 Systems, the first one Update my Tiles i want to draw if they are inside of my View:

protected override void Update(float elaspedTime, ref Map component)
        {
            ReadOnlySpan<Entity> tiles = mapTiles.GetEntities();
            Camera cameraData = camera.Get<Camera>();
            var tilesizex = 32;
            var tilesizey = 8;
            var XMapZeichnen = new Point((int)cameraData.VisibleArea.X / tilesizex, (int)(cameraData.VisibleArea.X + cameraData.VisibleArea.Width) / tilesizex);
            if (XMapZeichnen.X < 0) XMapZeichnen.X = 0;
            if (XMapZeichnen.Y > component.Size.X) XMapZeichnen.Y = component.Size.X;

            var YMapZeichnen = new Point((int)cameraData.VisibleArea.Y / tilesizey, (int)(cameraData.VisibleArea.Y + cameraData.VisibleArea.Height) / tilesizey);
            if (YMapZeichnen.X < 0) YMapZeichnen.X = 0;
            if (YMapZeichnen.Y > component.Size.Y) YMapZeichnen.Y = component.Size.Y;

            for (int i = YMapZeichnen.X; i < YMapZeichnen.Y; i++)
            {
                var tile = i * component.Size.X;
                for (int j = XMapZeichnen.X; j < XMapZeichnen.Y; j++)
                {
                    tiles[tile + j].Set<Show>();
                }
            }


        }

And my DrawSystem:

 [With(typeof(MapTile), typeof(MapTextureShared), typeof(Show))]
    public sealed class DrawMapSystem : AEntitySystem<float>
    {
        private readonly SpriteBatch _batch;
        private readonly TileProperty[] _tilePropertys;
        private readonly World _world;
    
    
        public DrawMapSystem(SpriteBatch batch, World world)
            : base(world)
        {
            _batch = batch;
            _tilePropertys = world.GetAllComponents<TileProperty>().ToArray();
            _world = world;


        }
             
        protected override void Update(float elaspedTime, in Entity entity)
        {
            ref MapTile mapTile = ref entity.Get<MapTile>();
            ref MapTextureShared mapTextureShared = ref entity.Get<MapTextureShared>();
            _batch.Draw(mapTextureShared.TextureSheet, mapTile.Position, _tilePropertys[mapTile.ID].Source, Color.White);
        }

        protected override void PreUpdate(float state)
        {


            _batch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend, SamplerState.PointClamp, null, null, null, _world.GetAllComponents<Camera>()[0].Transform);
        }

        protected override void PostUpdate(float state)
        {
        
            _batch.End();
        }

    }

And one of the Start of the new Update Cycle to do the following:

[With(typeof(Show))]
    public sealed class ShowSystem : AEntitySystem<float>
    {
        public ShowSystem(World world)
          : base(world)
        {


        }

        protected override void Update(float elaspedTime, in Entity entity)
        {
            entity.Remove<Show>();
        }
    }