g321cu

I just finished a new build where I included 3 x MSI G321CU monitors. I cant seem to figure out why they won't put out a signal when I restart the pc. My system is asus x670e mb, asus 4090 strix gpu, amd 7800x3d, g.skill ddr5 think like 6500 but not sure ATM. Had it originally on only 2 monitors...