Dell laptop cpu throttles below base frequency

Hi so I have a dell g5 15 intel i7 9750h rtx 2060 16gb ram 480gb ssd. When I stress test just the cpu it can run up to 90w for a short period and than it can sustain 75 to 80w which is pretty good. When both gpu and cpu are working then the cpu can run at about  60w give or take and on the edge of thermo throttling at about 99c. The problem is that after 10 or 15min the cpu drops to below 30w and the freq also below 2.6 ghz. The gpu never thermo throttles. Why does this happening? The cpu when it throttles to below 30w is at a temperature of 75c so it doesn't thermo throttle. Intel xtu says power limit throttling. I have a suspicion that it is because the laptop needs to be below 50c at places where the user might be touching but I want to know for sure and also to try and resolve it because it also throttles on games which is a big bummer.