I found this on King Arthur web site.
Don't know if it will solve your problem or not...
In this article they are trying for the crispy crust, not a soft one, but explains how to make it soft.
"Once the bread is baked, turn off the oven. Transfer the bread from pan (or stone) to a middle oven rack. Crack the oven door open a couple of inches (a folded potholder works well here), and let it cool right in the cooling oven.
Your goal: avoid condensation.
How does this help keep bread and other baked goods crisp? As the bread (or crackers, or cookies) cools, any leftover moisture in its interior migrates to the surface. If that moisture reaches the surface and hits cool air – e.g., typical room temperature – it condenses on the outer crust, making it soggy. If it hits warm air (your still-warm oven), it evaporates – leaving the crust crisp."