There are 2 different issues I believe:
If the beard gets cut, it should happen in a way, like a scissor does, also I believe that according to R' Feinstein, one needs to still feel the beard after shaving.
With the above mentioned points in mind the following 2 thing have to be taken are off:
The blades shouldn't be sharp to an extend where the beard gets cut before the hair is pushed against the side of the holes in the shaver head (the little hole through where the beard goes into the shaver), you can check this by removing the blade, and placing it e.g. on the back of your hand, and twisting the blades, against the growth of your hair (the blades must be rubbing scratching your skin. You should test each individual blade).
Now, to make sure that the beard doesn't get cut too short, you need to get rid of the lift and cut system.
When taking the blades in your hand, you will see that there are 2 'blades' on top of the other, but one of them has a part that sticks out above the other. (That means the blade that would touch your bears as first while shaving). Take a tool to remove the one sticking out (on all blades).
I would start by removing the secondary blade before checking the sharpness.