Question CPU clock speeds stuck at 800 Mhz

[cade_exe]

Hello everyone, I need some help with my CPU

I recently RMA'd my Intel i5 13600KF and recieved an i5 13600K in return. I installed it updated BIOS and everything seemed to be fine for a week or so.
Today i started my PC to find it painfully slow and while troubleshooting I noticed in HWmonitor that no matter the load, my clocks were stuck at 800Mhz,
after searching online and trying a few things the only "fix" was disabling my XMP.
However like the user that suggested it warned me this randomly stops working and clocks get stuck at 800Mhz again in addition to my RAM being slower than I'd like. (2133 instead of 3600)
Do any of you have an Idea what could be causing this or have any experience.

Additional Info:
Self built PC
RAM corsair vengeance rgp pro sl 16GB (2x8 GB) DDR4 3600MHz C18 kit (2 x for 32 GB)
OS Windows 10
GPU 3060ti (i know its a bottleneck in gaming but i didnt get to upgrade it yet)
Mobo Gigabyte Z690 UD DDR4
BIOS ver. F29g
Windows Power Plan is currently at balanced (changing it to performance didnt do anything)
there are no throttling issues my CPU is at a cool 36 C usually
thanks to recent Intel shenanigans i left all BIOS settings outside XMP at base or auto

previous issues: all clocks stuck at max at all times even in idle (no clue when i fixed this or how I just stopped monitoring it and it went away i think)

I hope some of you may be able to help, thanks in advance

 

[JohnBonhamsGhost]

my clocks were stuck at 800Mhz

if resetting BIOS to optimized defaults does not change anything;
then you either have some software loaded in Windows that is forcing the clock speed,
you have a faulty motherboard,
or a faulty CPU.

 

[uWebb429]

@cade_exe
Run ThrottleStop 9.6
https://www.techpowerup.com/download/techpowerup-throttlestop/

Open the ThrottleStop Limit Reasons window. Does it show BD PROCHOT glowing red? That is typically the reason why an Intel CPU gets stuck at 800 MHz. It is usually caused by a sensor on the motherboard that has failed. It tells the CPU to constantly throttle even though the CPU temperature is fine.

The CPU you got might be defective but it is usually the motherboard that causes this problem.

If ThrottleStop does not show BD PROCHOT then check the CORE column of Limit Reasons for anything else lighting up red.