M2 Pcie disables SATA on Z390 Taichi Ultimate

On a new build using the Z390 Taichi Ultimate I installed 2 M.2 drives, one on M2_1 and one on M2_3 (the drives are Samsung 970 EVO M.2 2280 PCIe).

Now I have found that SATA 0,1,4,5 are all disabled. Samsung Magician lists both M.2 drives as PCIe Gen 3X4.

I was under the impression that M.2 drives using PCIe would not disable the SATA ports. Am I wrong or am I doing something wrong?

Thanks for any insight!