hi , people think this is not normal because it doesn't have the same behaviour as their previous hardware (in fact it seems just an analysing problem of the numbers) ... but with the right tools , you can see their is nothing alarming
full speed clock 4.275Ghz , with 1.5V , in "idle" state, ok that seems weird but it's just a tool reporting, why not complaining to the maker of the tool , i explain, with that numbers in the same time you have a consumption of 5W ... so it isn't loaded at all... when the system is more loaded , the vcore decrease because of the load and because it need intensity, while clock decrease because of temps and intensity for same vcore but then it's what's called vdrop ... all of these are related
and i just saw that if not focusing on the tool the cpu idles better ... just a matter of tweaking at the end
your temps seems ok , but if you want to be reassured you can change your cooling system and/or decrease the offset in bios
i actually apply -0.05V offset to gain 5 degrees ,
at full load my cpu (3700x too) can up to 73° but it's currently at 29° (ryzen balanced power plan , my cooling system : h115i pro at "balanced" settings)
or you can choose to use the energy saver power plan when you don't need the full power of the cpu as it is efficient to work with (that wasn't the case with my last cpu that was really slowing down even for browsing web pages)
if your cpu clock goes down a lot while on load , it's surely because throttling because it's too hot, so better solution is to apply a correct cooling system ... don't forget you cpu overclocks itself , overclocking allways means more heat that's logical
there are several "solutions" to what people think is a problem
if you don't want to spend money with better cooling system : just go with throttling (that's what's intended to manage poor cooling system), or try undervolting with negative offset (maybe you will loose performance but maybe not so much as you thought)
if you have a little money go for a medium watercooling system to maximise the use of the cpu
people seems to forget that even it's 7nm , now they have more cores so temps can be expected be the same as previously while they had less cores , that's a choice not an issue at all