What kind of load are you trying to use? I've noted less usage in general as of a month back or such but can get it back up depending on what stuff I run, but it mostly seems limited to temperature hitting the limits restricting more power draw.
I assume you use the PB & PBO and eventually EDC bug? Not manual OC, would be utter weirdness if the restriction is related to Manual OC.
Gigabyte X570 AORUS XTREME, Ryzen 7 3800X PBO boost, 2x8GB 4866/1900 220.127.116.11.90.tRFC 680 1T 1.650V [Micron Rev.J]
4x8GB 3800/1900 18.104.22.168.66.tRFC 600 1T 1.700V Kingston HX434C19FB2K2/16 3466C19 1.2V (Micron Rev.E 19nm [D9VPP]),
2x8GB Kingston HX436C17FB3K2/16 3600C17 1.35V (Micron Rev.J 17nm),
2x8GB 3866/1933 22.214.171.124.60.tRFC 448 1T 1.590V Kingston HX436C17FB3K2/16 3600C17 1.35V (Hynix DJR 17nm)