Bouncing off of the deflector that violently is assuredly excessive carrier speed. The rifle is over gassed/under massed for the Green Tip load. I’d assume the steel case ammo is lower pressure, or hanging onto the chamber a bit more, so it’s not ejecting as powerfully - under gassed/over massed.
An adjustable gas block would be my answer for both conditions. I like H2 buffers to slow down the carrier speed and spread out the recoil impulse.