70% hydration,. with bread flour. Plenty of folding to where I get a really strong windowpane. I do bulk fermentation in fridge overnight, dough about double. Work it on the counter and get really good surface tension during shaping. Kept in banneton until double. As soon as I turn it out on my parchment paper to lower into my dutch over, it just slumps. Also, maybe related, my razor blade -- using either water or flour -- does not score sharply, but tends to snag.
I get a decent oven spring, but not sure if I'm expecting too much in terms of it keeping its shape. I can't imagine baking it on a stone without the support of the dutch oven.
Any thoughts on what I might be doing wrong?