asus prime b 550 m k

Hello everyone , I m new here so forgive my chaos , I have Asus prime motherboard B 550 m-k with last bios , and an apu Ryzen 4650 G + ripjaws 8*2 ddr4 ram cl16-3200mhz recently I bought Xpg s20g nvme wich is gen 3 by the way , I pluged in the first M2_1slot ; the problem is that...