Have to run at least first adrenaline for the full features of Wattman where you can use it properly. I am picking up a R9270 card in the next day or so & going load up either 17.12.1 or 18.2.1 drivers which I am running & arnt the best but stable drivers & wattman great for OC with ease.
I tried a clean install of the wattman drivers, did not work, every time I tried to change the frequency, the card clocks itself to 300/150.
Is this a UVD problem?
That's perfectly normal, cards down clock them self when not in use or in idle state.
If your card is gonna run at max speeds all the time you will be killing your power bill.
Its not a card issue or driver issue its how manufacturers made the cards. Download GPU and look for a little ? mark symbol and it explains a little better