Even though you didn't activate Wattman, seems like some parts of it runs in the background and is used by the Graphic's driver.
It is known that many people have issues when they use 3rd party Graphics controllers like MSI Afterburner or Asus Tweak II. They have shown to have some incompatibilities with Wattman even if Wattman is not installed. AMD Forum generally suggests to uninstall all 3rd party Graphic controller software.
You might try updating the Chipset (2018) for the SB990 Motherboard from AMD Support: Previous AMD Chipset Drivers ..
There also is a newer BIOS - F2 -5/19/2016 for your Motherboard. But it is mainly to do with the Motherboard's Killer LAN feature. Don't know if the new BIOS involves other updates to the motherboard besides the LAN feature.
I installed the Asus software to try and solve the problem. I see what your saying, but it wont solve the underlining issue.
I am downloading the drivers and see what happens. PC is tied up for about another hour before I can install the drivers. Addional, I found a site that lists the driver version for the SBS990 chipset driver in that package. It is 220.127.116.11. I hvae located the driver in my device manager and it is also 18.104.22.168. So as far as I can tell, I am running current drivers. It is something I do as habbit for all devices every 2 months if I dont get update notifications. Just run up the chipset installer. All chipset drivers were already uptodate. No need to install.
I also when you said the BIOS info, it made me realise I put the wrong motherboard details. I have now corrected that as the motherboard only has one BIOS atm. The Motherboards is a Gigabyte 990X-Gaming SLI. There is no BIOS update at this time.