What exactly is worse than before? The quality of cut? The tear out?
First you have to lower the blade all the way down. Then remove the aluminium panel on top. Insert the splinter guard and place the aluminium panel back. Turn on the saw and while the blade is spinning let the blade come up slowly so it cuts into the splinter guard.! --->
There is one thing you have to pay attention to. In order for the splinter guard to work optimal, it has to protrude slightly (0.3 mm) above the aluminium table top. In the picture below you can see two screws (8-2) that you can use to adjust the part that holds the splinter guard.
I never have a problem with the splinter guard. Only problem I had once was when I wanted to make a 45 degree cut and forgot the splinter guard was still there. You have to remove it when you cut under an angle. So I was twisting the knob and didn't understand why the blade wouldn't move, until I heard a snap and the splinter guard broke.