Are you relying on the boat inclinometer or a phone app?

Download the clinometer app and verify that your in-boat readings are correct. You will be chasing ghosts without verifying first... my boat was horribly inaccurate from the factory.

As everyone said, way too much center plate. Start at 25% which is the stock setting and then give that a ride. I wouldn't expect you would need to add more plate with the additional 500lbs sitting up front.