My John Deere belt and blade cut more evenly than this set (was a mulching kind). It's not cutting as evenly. Where the tires run this blade doesn't pull up the grass well enough to cut it at same height as where the tire doesn't run, whether the grass is wet or dry. Maybe blade doesn't have enough vacuuming effect. And, the belt may have some slippage due to it not having enough contact area with the pulleys.
Not sure this is the best combo for LA series John Deere rider