Hi there.
Msi b450 tomahawk + Ryzen 5 2600
If I increase the processor multiplier in bios (eg 4Ghz) I lose power saving.
So the clock and voltage are not turned back on either.
BUT..! If I set Cool & Quiet to auto in bios (not Enabled) then the clock will turn back on even if the voltage is off.
I've tried a lot of settings but can't find a solution.

Maybe someone knows what medicine is?

Don't use "Auto" it may be enabled one day and disable the next. Pick enabled or disabled, whichever gives you the action you want. Talking about what you mentioned with Cool & Quiet. I can't understand what you are asking here, so you'll need to explain it again with more detail.
In general, power saving features can be used with or without any overclock, the use of "Auto" may change how that seems to be to you, but you can use those kind of functions with or with an overclock you just have to enable or disable whatever you want.

I am not an AMD user, so someone who does use AMD will probably have to advise you on what exact settings you need to use, once you explain what you want a little bit differently.

Thanks for the answer! @Lost_N_BIOS
So. If I set the processor multiplier in the bios then it will lose the power saving. Even though I set any C-state or Cool & Quiet setting, the voltage remains static. As I went through and read on asus motherboards, this can be set and if the processor is not under load then the clock and voltage will turn back on. For me, only the clock switches back to 1550Hmz but the voltage remains static at 1.350V. I think this is not good for the processor. But this phenomenon is only at overclock. As soon as I touch the processor multiplier, I lose whatever down voltage control I set. I've tried many bios and many settings but can't find a solution.
Maybe the MSI board doesn't know that?
Maybe you need bios modding?
I read it afterwards and not only do I have it. Those with an MSI b450 tomahawk motherboard have the same problem.