Poticia

Our family bakes a traditional sweet bread on holidays and special occasions.  The dough uses lots of eggs and yeast and this time was left to rise in the refrigerator overnight.  It tasted great however it didn’t form nice loaves but flattened out.  About 6 loaves were baked on baking metal sheets.  After baking the loaves rose slightly but melted into each other to create a consolidated loaf the size of the baking sheet.  I’d appreciate any advice on why this may have happened and how I could bake it differently to obtain nice small oaves.