You also have the run once option.
You could also create a variable to track if all blocks are broken. Set it to 1 when all blocks are broken. Have a trigger that checks if the variable is 1, if so adds 10 to the score, then sets the variable back to 0. That may work for you.
The current issue is you are basically saying when all blocks are broken add 10 points, well every time the code runs through (each frame) it is still true. So you need a way of setting a condition that they are broken and then clearing it so the code doesn't keep running.