Yes, your local extension office suggested mulching blades, but it's not needed.
Just leaving the clippings on the lawn is satisfactory in recycling them.
So, first I would ditch the mulching blades, use a good set of normal blades and discharge out the side. See if that makes a difference first.
Also, the shallow decks of homeowner mowers need to be cleaned more often. Mulching compounds this issue. Take a good putty knife and clean the deck out also when you change the blades.
After that, and you still have issues, then think about a better mower.