For this case, please clean the golden finger of the RAM modules, then just connect one module. Then enter BIOS to press F6->F10 to save and restart the PC. After that, just enable the XMP function and press F10 to double check the frequency in BIOS and OS mode.
If it cannot help, please disable the XMP function, then adjust the "memory try it "or "DRAM frequency" option to try. In addition, please test one module in each DIMM slot one by one, then confirm that all of the slots are all right.
You can enter BIOS to disable the "Memory Fast Boot" option to try. In addition, please make sure that all of the power connectors on the MB have been connected to the power supply properly.
You can also send us a picture about your RAM sticker and take a picture in CPU-Z-> SPD.
PS: Please don't adjust the DRAM frequency/voltage/timing manually when you enable the XMP or memory try it option. If you have another more powerful power supply on hand, please have a try. Thanks!