Thank you for writing us back and sending in the videos, and pictures regarding your mower. First, I would like to complement you on a beautiful lawn. I showed the files to our model engineer and he notes that by the size and color of the blades that are being left behind the mower is pulling up a layer of thatch. Please note that the the mower is not leaving blades of green grass behind and the mower is pulling those strands from below the surface of the living green grass as you are passing by. Several actions can be taken to keep this from happening. Since you have a thick and lush yard you may need to mow more often, slow the pace especially as the bag becomes full, and de-thaching your lawn will bring that dead grass to the surface.