DRIVER_POWER_STATE_FAILURE in idle with Balanced power plan after overclock

[parmi]

Specs:

• CPU: i7-7700k @ 4.20 GHz (Turbo boost: 4.5GHz) [delidded]
• Mobo: Asus Maximus IX Extreme
• GPU: Gigabyte - GTX 1080 Ti Waterforce WB Xtreme Edition 11G
• RAM: 32GB - G.Skill - Trident Z RGB - DDR4 3600Mhz - 32GB (8GBx4) - 16-16-16-36
• PSU: Seasonic - PRIME 850 W Titanium
• Custom Cooling system:
• Radiator: x2 radiator (520x30x60mm)
• Radiator FAN: x8 Noctua (120x120x15mm)
• Pump: EK-XRES 140 Revo D5

After several attempts I thought my CPU is stable with these OC settings:

• Vcore: 1.430V
• CPU ratio: x50
• Cache ratio: x46
• AVX offset: x0
• XMP: Enabled - DDR4 3600Mhz - 32GB (8GBx4) - 16-16-16-36
• Vcore mode: Manual (override)
• LLC: 5 (on a scale of 1 to 8)
• VCCIO: 1.2625V
• VCCSA: 1.2750V
• iGPU: Enabled
• iGPU offset: Auto (0V)
• Windows power plan: High performance

I managed to pass a 12-hour stress test with Prime95 (Blend mode), also I left the PC in idle overnight and there was zero problem (no blue screen).

Today I tried to change the windows power plan from high performance to balanced mode, and as I expected the CPU clock kept jumping between 800MHz and 5GHz, while the cache clock between 800MHz and 4.6GHz, and the vcore (as expected) was constant all the time, note that the cache clock always stays 300 MHz below the CPU clock:

CPU clock	Cache clock
800 MHz	800 MHz
900 MHz	800 MHz
1.0 GHz	800 MHz
1.1 GHz	800 MHz
1.2 GHz to 4.9GHz	(CPU clock) - (300 MHz) -> 900 MHz to 4.6 GHz
5 GHz	4.6 GHz

The problem is that if I leave the system in idle in balanced mode, after 5-10 minutes the system always crashes with the same BSOD, DRIVER_POWER_STATE_FAILURE.

It seems that if the CPU clocks are not constant the system becomes unstable, but I can't figure out why, especially since the voltages are constant!

Any thoughts?