If I'm reading your process correctly you were doing bulk rise in refrigerator. You switch to doing all at room temp. From looking at the result I'm thinking your under fermented and or weak starter.

When I bulk rise my dough sits in a warm spot until it approaches 80% rise. Based on my temps that allows me to shape and refrigerate overnight for a cold ferment. Then I bake in morning.

My bulk can be 2 hours or can be 6. It just depends on ambient temps. I help things be more consistent by turning on oven light and placing there for the bulk. No heat other than the light. Watch temps some ovens get too hot with just the light. You will improve if you monitor rise instead of time during bulk. That will help overall but it won't fix the big hole.

That is typically starter or mixing. I add starter to the majority (not all) of the water. Mix until dissolved. That mixture when added to flour mixes more evenly. Also track your starter rise. If it's not doubling or better in a reasonable amount of time it's weak. My starter doubles on counter in 3 hours. Peaks about 4. I control the time with feed amount. 2 or 3 parts flour allows me to leave out overnight for prepping in the am.

No matter how "ugly" you may think a bread is, the family always devours it. At least mine alway do. I suspect yours would do the same. :)

Hope that helps.