If you had cared to check the memory QVL posted by ASUS for your WS 299 SAGE/10G motherboard, you will find that the qualified DDR4 memory modules at 4000 and above are all single-ranked and 8GB in capacity. The memory sticks in your Dominator Platinum CMT32GX4M2K4000C19 2x16GB memory kit are dual-ranked and they are not in the QVL.
I've also discovered empirically that 4000 dual-ranked (e.g. 16GB) memory is virtually impossible to get working with any system. I have a Vengeance LPX CMK32GX4M2F4000C19 2x16GB kit that cannot run at 4000 (XMP profile) with any of my Z390 ASUS or ASRock motherboards and Core i7-8700K & i7-8700T processors. The upper operational memory speed limit for dual-ranked 16GB memory appears to be 3600 or 3733 in specific system configurations.
So it looks like one often cannot achieve both top memory capacity and top memory speed with the same system. This is indicated by the memory QVL lists of various X299 and Z390 motherboards not showing any qualified 16GB (dual-ranked) modules above 3800. If you want 4000 or even higher speed you'll need to stick with 8GB (single-ranked) modules. With 16GB (dual-ranked) modules you'll have to settle for 3733 or 3800 at the highest.
