I'm having a weird problem. I'm using two 280x in crossfire, and when I try to view the secondary card in AMD OverDrive it shows 0% on activity, 0MHz on GPU and Memory and 0 degrees on temp. Fan activity is always 20%, and if I try to change it it reverts back. If I try to view these stats in GPU-Z it's the same, no readings. I'm using the latest 16.3 drivers.
If I revert back to 15.12 drivers however, suddenly I get readings from both AMD OverDrive and GPU-Z as normal, and I can control the fan again. I don't seem to be able to get readings from any later version. I tried searching for it but it doesn't seem like a common problem. Does anybody know how to resolve this? Here are the cards in GPU-Z (the Hynix one is the primary):