make/model of power supply?
How much system RAM are you running and at what speed is it actually running at? (Task Manager>Performance>Memory)
Do you have "Above 4G Decoding" enabled in your BIOS? (Smart Access Memory enabled?)
Is your motherboard's BIOS up to date?
Are you running the latest AM4 Chipset drivers from AMD.com?
Run the program called DDU (Display Driver Uninstaller) to remove all things AMD/Nvidia GPU driver related ... reboot .. and THEN install latest drivers from AMD.com