They are floating to the top. To stop this, you can try soaking them first in a simple sugar water syrup, or even add liquor like rum and spices. Soaking them for a few hours could do the trick, but I recommend overnight.
Make sure the hook is going all the way down. Some clasps will only close completely in one direction. In other words, take out the hook, turn it 180 and...
You should bake your bread as close to the serving day as possible. If you're pressed for time, you can make it 2 days in advance, but make sure you...