Tight crumb on WW Sourdough Loaf

I need some tips on my 100% WW sourdough. I autolysed for 1 hour with the flour and water only, then did 4 sets of stretch and fold over a period of 2 hours, and let it rise for another 2 hours before I put it into the fridge for 12 hours. I took it out to let it finish its first proof on the counter for another 3 hours. Then, I did a pre-shape and put it back into the bowl to rise for another 2 hours while the dutch oven was preheating at 500F. I couldn;t tell whether the final proof was over or not because the surface tension of the dough would make it spring back no matter what stage the dough actually was in. I baked the bread for 20 minutes at 475 lid-on, then for another 30 minutes lid off at 450. I've gotten a slightly more open crumb with this flour in the past, so I'm not sure where I went wrong. 

RECIPE: 

100g sourdough starter

420g WW Bread Flour

373g water

9g salt