I built a system with Gigabyte B450 Auros M, Ryzen 5 3400G, G.Skill Flare X 3200 CL14 2X 16GB, 3X Arctic 120mm F12 PWM. The OS is Windows 10 20H2 and the latest Radeon and chipset drivers are installed.
When I enable XMP 3200 @1.35V, the system runs fine, except it crashes with a black screen when it's idle. According to Windows Reliability History, it was not properly shut down. When I initially set up the system, I set the power plan to high performance, because I'm not concerned about power consumption.
I noticed that the chipset drivers includes the AMD Ryzen Balanced Power Plan. I'm not clear if this power plan applies for a Zen+ processor. I read this post: https://www.reddit.com/r/Amd/comments/a9q96u/is_the_ryzen_balanced_power_plan_still_relevant/. It's from a couple of years ago, so I'm wondering if it's still applicable.
Also, I've read about C-state control and Power Supply Idle Control, wondering if either of these settings is related to the computer crashing.
Ryzen 5 3400G / Gigabyte B450 Auros M / G.Skill Flare X 3200 CL14 2X 16GB / 3X Arctic 120mm F12 PWM