I am having the exact same issue. I have an Auros x570 Ultra with a Ryzen 3900x and two sticks of 8 gb Viper Steel Series DDR4 4400MHz.
I cannot overclock via the BIOS. If I make any changes at all in the BIOS, they are not saved. I've been using AMD Ryzen Master and have overclocked the CPU to 4.6 ghz. However, no changes whatsoever to the memory sticks are stable. Either the machine will not start, or it does start, but opening Ryzen Master again after the change results in a hard crash to a powered-off state.