Complete Beginner - No spring & undercooked! : vimarsana.com

Hi All, Please forgive the very basic questions I am completely new to making bread!I have tried to follow this recipe: https://www.bakewithjack.co.uk/blog-1/simple-loaf-recipe Two minor adjustments:Half all quantities Dutch Oven in an oven at 230C rather than bread tinI scored the dough immediately before putting into the oven but, as can be seen from this picture, the loaf