CPU has been running for months with a high LLC setting, its fair to assume that it has been degraded to some extent, unless exceptional cooling has been used and the processor kept at a very low temperature. Lowering the voltage will not help, increasing it will mitigate until the CPU gets further damaged - it's a snowball. The wisest course of action is to simply dial back the clocks and voltage a little bit, and enjoy the processor for what it is. You're not going to have a massive general performance or game frame rate loss by shaving 200-300 MHz out of that processor, in fact, I doubt you'd be able to tell most of the time, yet it will be much nicer to the silicon, closer to the spec and significantly easier to stabilize.
Let's be frank: Frequencies in excess of 5 GHz are simply not needed on a Comet Lake processor, even if I understand it's a point of pride for certain Core i9 users. Well I got news for you: running those giga high frequencies isn't gonna make your processor better than a Ryzen at multithreaded benchmarks. Voltage is not everything, LLC violates the specification for load-line and increases transient current, which is what causes electromigration to begin with. The mechanics behind it are known as
Black's equation, and in essence, the longer the processor is exposed to a high current at warmer temperatures, the quicker it will deteriorate. Vdrop mechanics are intended precisely to counter that as load (and current strain) increases, LLC may help stabilize a processor but it should never be used at aggressive settings because it's just as violent as putting say, 1.6 volts onto the processor to begin with, if not worse.
I've done that folly to my Core i7-990X back in the day, I learned this the hard way. When it was new it would run stock at below one volt and would bench at 4.8 GHz around 1.375v. The last time I used it, it would crash at 1.2v at stock and would need 1.55v for 4.4 GHz, and it would still crash. And yes, I chucked electricity quite happily at it for many years to get to that point. I just haven't found the heart to make a keychain out of it yet, it was the only part out of my old X58 kit I haven't sold because, well, it's junked.
Succinct and to the point, I suggest OP follow our advice
