cuts

Does anyone have the problem of slashes on the loaf closing?? Mine open quite nicely then close up after about 10 mins into the bake. I don’t think it’s a matter of my cuts being too shallow. 

And what is the normal sequence? Oven spring preceding/ followed by/ accompanied with the opening?

I have a over-proofing problem but I wonder if too much steam or too little has something to do with it as well. Help!