First Ryzen Master is not yet fully compatible with Windows 11 so until AMD comes out with a Windows 11 version everyone will have to be patient.
In my case I installed Ryzen Master when I had Windows 10 and when I did a In-Place Windows upgrade to Windows 11 it continued to work as expected. But I have a feeling that if I have to install Ryzen Master again while in Windows 11 I will have installation issues like other Users.
NOTE: Can't you do those type of settings in BIOS itself?
Especially concerning Overclocking or change RAM voltages?
In BIOS you should be able to change the CPU voltages also.
Those type of changes is better done in BIOS instead of through Ryzen Master.