Hi LionAlonso
Welcome to the ROG forum,
I'll take it 1.80v is a typo otherwise you would have got a cpu overvoltage error.
It's normal for your cpu to draw a little more voltage than what you set but to counter act this you can use adaptive mode with an offset like you're doing and/or also lower the LLC (Load Line Calibration) to level 1, on auto it's likely contributing to the voltage overshoot.
LLC is found on the extreme tweaker tab in the DiGi+ section at the top.
You're doing the right thing by finding the lowest possible stable voltage, 64c is the max safe voltage for the 6700k, so while 65c is ok your temps will drop if you're able to run at a lower voltage.
Try this and give us an update if you have any questions please ask.
🙂