For CPUs that are not R5, R7 or R9, that motherboard supports up to 3466mhz memory modules. So run them at 3466mhz.
Enable the A-XMP profile, then manually change the memory speed to 3466mhz, then save settings and exit BIOS.
If you have problems then we will need to know the exact model of the memory kit you are trying to use with this motherboard. Not all memory is compatible with all motherboards, chipsets or CPUs. Or even when it IS compatible, it doesn't always play nice with them. Validated memory, especially on Ryzen platforms, from the QVL or the memory manufacturers compatibility lists is important once you get past about 2666mhz. Sometimes even below those speeds.