Crumb and Spring

I’m in the process of reviving an old basic formula that I used years ago and it is not going well. All things considered I am stumped.

FORMULA:
70% Hydration Biga/Poolish (made with UB AP & 12% UB BF) not together but have made both variants. (Average 12hr old at 68-70°f
500g Flour -UBAP-Bleached and Un bleached Bread 12% and Bleached HG 14% (all in separate attempts)
100g Biga
360g H20 and 390g
11g Salt
2.5-3g ADY

I have a bunch of photos of the results and way more info but I first wanted to ask a few questions. I have only recently baked using a Dutch oven for bread, in the past this formula worked well for my Woodfired Brick oven. I’m currently just trying to get back into the swing of things and using the DO to contain steam because the home oven is a convection/static oven that is not possible to turn off the cooling fan when in static mode. Given that formula there is no reason why at this point believe the Brick oven is a factor in my issues. It should be just fine with the home oven certainly not the same but close enough.

The DO is resting on a baking tray lined with 1.5” brick. The brick was an attempt to regulate the oven temperature because it is possibly the most uneven oven I’ve used, it solved that issue. It’s a newer kitchen aid double stack… horrible ovens. lol

I had reasonable success with that setup in terms of oven spring with just some generic grocery store unbleached AP (protein content unknown) I then started to focus on opening up the crumb it was nice and even but way too tight for what I’m try to get like before.

I switched to KA unbleached bread 12.5% and it opened up a bit. I’m almost certain previously I used a HG around 13-14% but not positive my notes don’t reflect that but the brand I was using only came in a bleached HG so it is most likely.

So I purchased a HG and a Bread flour and tried that and I literally got no to a tiny bit of spring.

My feel for bulk and proving times is very rusty and I have not ruled out those factors with the newer flours results but I did not have them with the generic or KA so I don’t think I’m that far off, at least not far enough to warrant the flat and short spring loves.

I have adjusted times for the stronger flours but I don’t think that is where the issue lies. But something is still not right.

The other day I did a test with just a straight dough at RT all the way and it came out reasonably good. Good spring crumb tighter as expected given its overall time.

I temped the DO (internal) prior to loading it to ensure it was up to temp 425-450°f and in all instances, reasonable results in particular spring and complete failure no spring the temp was consistent. Despite this I am leaning towards the possibility it might just be too hot and the crust is setting too soon. Is this reasonable? The twist is the pictured loaf was at those temps and it clearly did not set too soon or at least not as soon as the others using the formula above.

I realize there needs to be more information to diagnose my issues but as a starting point can anyone speculate?

Thank you.