Question i9 10900k suddenly overheating?

Feb 11, 2021

so I am creating this thread because I don't know what else I can do.
I bought a i9 10900k with a ASUS z490 F Gaming and a Kraken x73 AIO as an upgrade 1,5-2 weeks ago.
I received my parts, replaced my. old stuff with the new stuff and got to overclocking.
To give you some more information:
LLC on Level 6
1.32 Vcore
5.2GHz allcore
No AVX offset.

The first few days the system ran good.
Max temp was 85°c when running Cinebench R20 in a loop for 20 mins.

Now today/yesterday, out of nowhere my CPU goes up to 80-90 degrees while playing Apex Legends.
Stresstesting with Cinebench R20 immediately jumps to 90+°c and thermal throttles.

After some more testing I remounted my AIO but the problem persists.
I changed the frequency down to 1.2 vcore and 3.7 ghz and still the same result.The pump is still making noise (I guess, never really noticed anything) and idle temps are down in the 30-35°c.

I really don't know what the hell is wrong with my system because everything makes no sense.
If my AIO pump would be bricked, idle temps should also be higher than 30-35°c?

I appreciate any help in any form because I can't wrap my head around what is going on.

ps: sorry for any misspelling or wrong usage of words. I'm not a native English speaker.