I rolled my pc back to Windows 8.1 it was shipped with and also the original AMD drivers recommended by the manufacturer Lenovo on their website. It now uses the M260 but it's not great. Will buy a better pc without an AMD APU next time
I am having exactly same problem but with an AMD APU with integrated graphics and a Radeon M260. Games are not using the M260. If I find a solution I will post. Using latest Adrenaline 17.12.1 drivers