Question ASUS Vivobook pro 17 suddenly started overheating

Aug 30, 2020

My laptop vivobook pro 17:
CPU: intel i7-8550u
GPU: GTX 1050 4 gb
motherboard: ASUSTek COMPUTER INC. X705UDR
RAM: 16 gb

started suddenly overheating. One week ago I have replaced thermal paste and undervolt CPU for 0,075V and package temperature on benchmarking droped from 86°C to 74°C. But yesterday I ran benchmarking again and went out of room and when I came back the highest temperature was 100°C. From then I was paying attention on temperature all the time and realized that is overheating very bad. I even have cooling pad so I realy don't know what could cause this.

Thanks in advance.