Ken Forkish’s Overnight White Bread - Overproofed, underproofed, or something else?

This was my first attempt in a while at the Overnight White Bread from FSWY.

500g King Arthur Bread Flour 390g 92 F water Autolyzed for 25 minutes 2tsp salt 1/8th tsp yeast

Bulk ferment was 12 hours overnight in the oven with the light on, because it’s cold where I am now, with four folding periods in the first two hours.

In the morning it didn’t really look like it had tripled in size, maybe 2.5x, but there were huge bubbles sticking out of the top so I shaped it anyway and gave it another 60 minute rise while my cast iron Dutch oven preheated to 475 F. After 60 minutes the finger dent test showed the dough barely bouncing back at all, so I rushed it into the oven and baked it for 30 minutes lid on, 25 off.

It’s not…bad, exactly, but the texture is a little gummy and the big holes at the bottom obviously point to something being wrong. Any suggestions?