Your bed is almost flat. It is much better than mine. I have a high spot in one place and a low spot in another place. The only issue I see with your bed is your right hand side looks a little bit low. Can you level that back left corner a little bit more? It should be OK where it is at, but everything else looks pretty good. It seems you should be able to raise the back left just .2 or .3 mm and have everything really good.

I don't know what is causing your bed leveling problems. It might be time to make a short video of it doing that same print you have up above so we can see how the z axis is compensating and what the plastic looks like as it comes out of the nozzle.