Sorry, If I sounded rude, it was unintentional.
Can you upload a image of Ryzen Master onscreen so that people here in the Forum can see what you are seeing? Where it shows the sliders for Memory and Voltages?
I don't have Ryzen Master installed, hopefully someone knowledgeable might be able to give some insight as to why you can't adjust the iGPU voltages on a APU installed on a Desktop.
This is beginning to sound like the type of question the AMD Support can answer you. Send an email to AMD Support here: Email Form . This is the best method to get a reply back. They might be able to explain why you voltages is disabled on your Computer setup.