I just built a new pc. On first day cpu ran 75 to 80c while gaming, then after pc slept over night, cpu overheated to 95 to 100c. So I changed out paste, using pea size. Started pc up, played a game with 75 to 80c again, next day , back to 100c. Not sure if I just need to buy a different cpu cooler or what.
Max thermal for the Intel Core i9-10850K is 100C. so you are close. The Hyper 212 is insufficient.
The Intel Core i9-10850K does run hot under load so a Noctua solution would help.
You can gain up to 10C using a good quality thermal paste such as AS5, MX4 or Thermal grizzly. Thermal conductivity is measured in watts per meter-kelvin (W/(m⋅K)). All the above are rated above 8W/(m⋅K).
Some other brands are rated below 2W/(m⋅K) which are crap.
A small pea size blob spread sparingly helps as it is there to fill the tiniest of voids.