Stodgy crumpet-like crumb in overnight white
There are two likely causes:

 Insufficient gluten development. 

 Wrong quantities (probably too much flour): you don't mention how you measured the flour. Measuring by volume is notoriously inaccurate. It is best to use weights for everything, including water.
 Weak flour: AP flour has less protein than bread flour, so there is less gluten development.
 Strong white bread flour needs a lot of kneading, or, for no-knead methods, several shorter kneads with plenty of time in between for the yeast to act and the gluten to develop. If you only knead once, I suggest at least 10 minutes. For very wet doughs, pouring the dough out of the bowl and using a stretch and fold technique works well. (It is almost impossible to overknead by hand.) But the autolysis and overnight fermentation should have helped here.

 Not enough heat in the oven. Did you use a preheated baking tray or a pizza stone? If the bottom of the loaf was particularly gummy, it may be that not enough heat got to the loaf. Generally it's better not to use the fan in a fan oven when baking bread. You want humidity (hence the container of boiling water), and the fan will disperse the water vapour. An alternative to messing around with boiling water is to use a preheated Dutch oven. This ensures all-round heat gets to the bread, which also cooks in a moist environment.

For more advice on trouble-shooting bread dough, I recommend the serious eats article.