Are you using the Windows Balance plan or did you install Ryzen Master and are using Ryzen Balanced plan. If not then do that and see if it helps.
If that does not help it may just be how your motherboard is managing the processor. It is the very bottom of the line of compatibility and was truly designed as a the super budget option for 1st gen Ryzen. It could be having an issues with the Zen2 chip. Many of those boards while having bios updates that will run the chips don't have good enough VRMs to run them well. It is always possible the chip can be the issue too or even something messed up in the Windows registry.
I wold contact the support department of your motherboard maker. They should be able to assist in isolating the problem and if it is the motherboard offer an RMA if it is under warranty still.