Mower does not mulch properly

I asked FixBot (Ai) your question with its reply in italics. Be aware of Ai mistakes.

As shown, it's the image below correct for your model lawn mower/mulcher? It's the mulch cover attached? Do you have two blades, one for mowing, the other for mulching? Are both new and sharp?

When a push lawn mower does not mulch properly, it is usually caused by wet grass, grass buildup under the deck, a dull or incorrect blade, or an unsealed mulch plug.

To restore proper mulching performance, check and address these common factors:

1. Damp or Wet Grass: Wet clippings stick together and clump instead of circulating and being recut ¹. Wait until the lawn is dry before mowing.
2. Deck Buildup: Accumulated grass clippings underneath the cutting deck restrict airflow. Stop the engine, disconnect the spark plug wire for safety, and scrape away any caked-on grass residue.
3. Blade Condition and Type: Standard high-lift blades or dull mulching blades tear grass rather than cutting it multiple times. Ensure you have a sharp mulching blade installed ².
4. Mulch Plug Alignment: Confirm that the mulch plug is properly fitted and inserted, and that the discharge door is fully closed so clippings cannot escape ².

Mowing Pace and Height: Follow the one-third rule by not cutting too much grass height at once, and slow down your walking speed to give the blade adequate time to process the clippings ³.