Sonora Sourdough Loaf Underproofed?

Hello everyone! 

Here is my attempt at a 100% Sonora Wheat loaf using a local Sonora grain which clocks at around 15.75% protein!

I did a cold extended autolyse and a cold bulk fermentation and a cold final proof.

100% Sonora Wheat

90% Hydration

20% Sourdough Starter @100% Hydration

2.3% Salt

I baked it in a preheated combo cooker at 500F and then once I popped the loaf in I turned it down to 450F then after removing the lid turned it down to 425F.

How does my crumb look is it over proofed or under proofed I feel that something was not right with it as there was a decent size whole throughout the entire loaf in a corner of it

Cheers!