Area 51 Laptop thermal issue help

Area 51 18" I9 275hx 5090 64GB

I bought this laptop about 8 months ago and haven't had issues with temps this high. Previously the highest I'd see while gaming (D4, POE, Heroes of the Storm) were high 80s and that was in performance mode with the fans not at max. Here in the last few days the temps have spiked very high playing the new POE league

Nothing is blocking the vents. The vents are clear of dust. I have the laptop elevated. Any idea what the problem and remedy is?

Update 1: dell sent a tech out to replace the heatsink assembly and repaste.

Update 2: the prior fix didn't change anything so Dell offered to repair in house. The laptop was shipped to them and within a week I received it back with a new motherboard.

update 3: laptop crashed to a black screen during first gaming session and said device ran into an issue and couldn't be repaired. Event viewer shower PCI Express issues and Dynamic Tuning issues. Windows will not update. Reached back out to Dell. I'm guessing I will be sending back in. I'll update accordingly.