Must be a difference in the behavior of these games according to there RTP setting, I have played these quite a bit at a place known for having machines set at 85% RTP and I have not or rarely seen the same behavior as being described here.
IE grand is not progressive stays @8000, Rarely or never see a screen with a major loaded and have never seen anyone get a full screen bingo, I know this is a small sample but sure seems to be different from what I see.