If you are going to score it then put it seam side up, that way the bread will only break on your score rather than the other weak points from the seam.
Your crust could be forming too quickly, essentially sealing the score and causing pressure to burst out of other places. You could try more steam to keep the crust softer and allow the score to continue to open up as the bread cooks?
If you are going to score it then put it seam side up, that way the bread will only break on your score rather than the other weak points from the seam.