Does it sound like a faulty cpu to you?
There's a lot of variables with these high-end CPUs (i.e. quality of the motherboard VRM/power delivery and the PSU, the PSU's reaction to instantaneous load, motherboard settings, cooling and cooling profile e.g. how quickly it reacts to load, the memory and memory settings, the individual workload and how demanding it is), so it is
really hard to say.
What wookiee87 said might be right here, that Intel just can't test these CPUs thoroughly enough, or that their test conditions for those boost clocks are too different to their standard usage in the "real world".
It was a lot easier when CPUs only had 4 cores and a small variance in power/heat output, but they can use anything from 30 - 400 watts nowadays and have
massive variance in volts and frequencies. Heck, the 14900K effectively has 2 different CPUs/architectures in one. They also have several different boost technologies, the standard turbo boost and TVB and the instability could be anywhere in there.