After more tests, it seems auto-tuning IS working ...

But I can't make the -cvddc switch to work
If I run Claymore for a minute, it sets correct core voltage, I stop it and run Phoenix - doesn't matter if I use cvddc or not - it will use what Claymore had set. Same if set with Afterburner.

Are there some requirements for OS/Driver combo in order to use this switch? I tried on 7 and 10, relatively older drivers because I don't update what runs ok.