My 6th plain loaf, I tried a bigger recipe this time for a larger loaf, thoughts on the crumb?

150g starter
400g water
20g oil
675g flour
16g salt

I mixed the dough and rested half an hour, did 4 sets of stretch and folds 30 minutes apart and then fermented in proofing box at 22 Celsius for 12 hours. Shaped, cold proofed for 12 hours then scored and baked at 250 celcius in a preheated Dutch oven for 35 minutes with the lid on and 20 minutes with the lid off. I cooked for two hours before cutting.
This was a bigger loaf so it took longer to ferment and bake than my usual size but I feel like it looks underfermented? I should have set my proofing box at a higher temperature but I was worried about it going over whilst I was at work.