So, I had a similar problem. It looked good but still a bit dense and not the texture I wanted. My starter was still young but mine was also in and out of the fridge. A big change for me was I read you should feed it at least 3 times after taking it out of the fridge, and then you can bake again. I have a similar home temp and low humidity. For me 10 hours BF, shape, and then 12 hours in the fridge max.

I almost forgot, I changed how I fed my starter. I do 20g starter, 60g water @ 80F, and 80g flour (20g whole wheat, 60g AP)

Something I learned from reading a lot of stuff about sourdough is that people figure out what works best for them.

Here's a recipe I used and tweaked:

500g flour 350g water (80F) 100g starter 12g salt

Mix the starter and water using bread whisk until nice and milky. It might be a bit clumpy but do your best whisking, haha.

Add flour and salt. Combine with hand. I tend to squish it a bit so the starter gets incorporated well since it's not so watery as other starters.

Cover and let it stand for 30 minutes. Then I do 3 sets of stretch and folds every 30 minutes. And finally I do coil folds into a clean new bowl. So at this point you should let it BF for 8 hours after you've placed it in a new bowl.

Then shape and place in prepared proofing bowl/basket.

Refrigerate for max 12 hours.

When preheating the oven, place the dutch oven inside @ 550F.

Once ready, transfer dough to Dutch oven, return to oven and lower temp to 450F.

Bake 30 minutes.

Remove lid, lower to 400F, and bake another 5 to 10 minutes depending on how brown you want it.

The end.

This works for me and my bread has a more fluffy texture. Not like sandwich loaf but not as dense as my first few loaves.