Hi,
After a lot of testing and struggling with this gpu I've come to this solution
1.1 Select in BIOS -> PCI-E 3
1.2 DDU all of the GPU drivers (Intel, Nvidia, AMD)
2. Latest driver update 19.12.1
3. Load up the profile I've uploaded in Wattman (Wattman is in AMD Radeon settings/Gaming/Game Explorer/Global Settings/Global Wattman)
The GPU I'm using is Sapphire Radeon RX 5700 XT Nitro+
Hope it helps.