Ryzen 5 5600X,MSI B550 only 1 RAM slot working

If only one DRAM, please install to DIMM_A2 slot If two DRAMs Stick PCs; Headphones & Headsets; Optical Drives & Storage; All-in-One

1 stick of ram in it has to be 2 sticks buttt The 2nd stick doesn't register only runs 4gb it also won't work with a single stick of 8gb ram

which m2 slot to use two sticks kit of 16GB each as an upgrade and one 1TB Transdent SSD, which I installed via SSD NVMe adapter in the secondary PCIe slot I used it

which slot machines have the highest rtp I read in multiple places that RAM could be upgraded to 16MB, so I bought both 4MB and 8MB sticks I have tried multiple configurations with