Cutting problem e80 module

Hello, I have a problem with my E80 laser module. It is not cutting wood properly.

I am cutting 3 mm MDF. I set the speed to 4mm/s and make 5 passes for each piece, but it still does not cut through properly.

I have also installed a new lens, but the problem is still there.

The E80 laser module is brand new. I purchased it about 4 months ago, and I received it approximately 4 months ago.

Could you please tell me what might be causing this problem and what I should check or adjust?