Using the AMD’s Adrenalin Drives is causing only singular GPU to render.
Unsure if anyone is experiencing similar issue.
With any blender 2.79 or any builds after (haven’t tried with earlier ones) my (temporary) dual GPU setup is rendering a single tile. Confirmed in GPU-Z and other monitoring tools that only singular GPU is used.
In user profiles tab, two devices are visible. I unselect one, blender unselects both. I select one, and blender selects both.