Do a CMOS reset. Something's not right and that would probably be the best place to start.
You said you have BIOS and drivers up to date...I assume that also means chipset driver that you got from the AMD support website. Run the Ryzen Balanced power plan, installed by the chipset driver, and do not make changes to the CPU Power States settings.
Once CMOS is reset be sure to leave CPU multiplier and VCore voltage on AUTO and enable the following: AMD CoolnQuiet, Global C States, Processor CPPC and CPPC Preferred Cores.
Those settings should help your processor boost as designed. It only boosts to highest clocks for light bursty loads on a single core at a time but it should work most heavier processing loads around from 3.8-4.1Ghz range.