Hi markmn123
Welcome to the ROG forum !
In the Digi+ section of the bios set LLC to level 3 or 4, if it's on auto it's likely running at level 9 and the higher the LLC the more it will overshoot the voltage you set.
After changing that run a test and see what the voltage goes to, if it's still overshooting a fair amount you can set the cpu voltage to adaptive mode and use a negative offset.
So just subtract 1.20v from what it's showing during the test and enter that amount as a negative offset.
For example if the cpu is drawing 1.350v during the test, set a negative offset of -0.150v this should keep it at or close to 1.20v.