X300, 42" deck with mulch kit.
Thought it was the blades, so i bought new blades from the dealer. (AM140973) blades are installed on correct side and facing the proper direction.
right side cuts what appears to be perfectly, yet the left side looks like it's accomplishing nothing.
Blades are both spinning, I cleaned out the deck.
There is no looseness or wobble when the blades spin.
also, the blades appear to perfectly align with each other in the middle for comparison.
not sure how clear it will come across in the photo.