People often misread what their monitors are telling them.
They see their systems doing little work, and think "oh it shouldn't need much voltage"
Ryzen Master is reporting the Maximum voltage applied to any one core.
If you had a loaded processor, running many cores, it would consume much more current, however the CPU might down volt those cores just a touch. So when running 8 cores you might run 1.35 volts. However, it is when your system appears idle, that it gets a chance to dispatch work to only a single core that it will ramp it up to 1.4+ volts and run it at 4.2+ GHz.
If you are nervous, Watch your workload in Ryzen Master, Expand the CCD's so you can see the bar graphs for the individual cores. Under the Bar graphs you will see not only Peak Voltage but also Average voltage.
As you watch long enough, you will sense the system only volts to those levels on just a few cores. Remember, you and your Monitor are not getting the full picture. These cores can be dispatched, put to sleep, and dispatched again at a different frequency and you wouldn't catch it.