Question CPU slows down after 2 minutes of gameplay

[purepure]

Laptop: Asus ROG GA502DU

When playing any video game from any launcher/game store everything is running fine for 2 mins, but then the entire machine just grinds to a stop and essentially freezes. When this happens, Task Manager reports the CPU speed dropped from something typical like 3.2x GHz all the way down to 0.34GHz.
As far as I know there is nothing weird installed, all drivers and Windows is up to date. I've only got 17 GB of SSD storage left but I don't think that's the issue. RAM usage never maxes out.

I have no idea if this is hardware or software. My only thought is maybe my CPU is getting too hot? CPUID reports 85 highs, is that too hot? Maximum it reaches is 90.
Although the graphic chips (the CPU and the 1660ti one) get about as hot too.

Would it be a case of replying thermal paste maybe? My only other call of action is to just reinstall Windows, and if it continues to happen I can narrow it down to being some hardware issue but I want to try and avoid that as to not reinstall everything.

Thanks for taking your time to read/help.

[Mod edit: changed title for clarity from "CPU Clock speed throttles down every 2 minutes when playing any game? Is the CPU running too hot or something else?".]

 

[redmark_]

Try reapplying the thermal paste and see if it helps.
I recall a buddy's PC having some kind of problem like that once, but problems like then sometimes tend to vary between different PCs, sometimes it isn't caused by the same thing.