Make sure your motherboards BIOS is up to date
Is this a CLEAN install of Windows?
https://rtech.support/books/how-to-and-guides/page/clean-installing-windows-10
..or is it carried over from a previous build?
Make sure you have the latest AM4 chipset drivers installed from AMD.com
Make sure your memory is installed in slots A2/B2 (2nd and 4th slots away from the CPU socket)
You can run DDU and uninstall all past/present AMD iGPU drivers .. reboot .. and THEN install latest graphic drivers from AMD.com
Check your Device Manager ..under View , enable "show hidden devices" and look under Display adapters .. if you have any greyed out entries showing here .. remove/uninstall them