Sorry for the MASSIVE DOWNER. This is one that nobody like to hear, but it's true. Before your bread has rested up and cooled, it'll still be quite doughy when you eat it. If you can resist it, let your loaf cool fully before tucking in. It's SO worth the wait, and only then will it show you what it's truly made of!
The more I make sourdough the more I realise that succes is down to two things: the multiplication of yeast and building structure in your dough while that is happening. Once you have the principle, and as long as those two things happen, your loaf WILL puff up and WILL hold a nice shape too. You win! Then, when you really get with it, you are free to make your own sourdough process fit around your life, instead of the other way around.