Final Disappointment

Toast

My last sourdough preparations were going so well.

My final proving had risen more than usual, and the dough rolled out perfectly from by banneton into my Dutch Oven due to its covering of semolina ..... but the final loaf hadn't risen and was flat, hard and moist, with the toughest crust ever.

What am I doing wrong ?

With no photos, recipe or procedure I'd say over fermenting/proofing.

Please can you provide as much info as possible.