NVME SSD not running in X4

[XiiXii808]

Currently I'm using a Gigabyte B550M DS3H MATX motherboard, in February I got a 980 pro Gen 4 SSD and put it in the Gen 4 X4 slot below the CPU and below the 980 pro NVME is my 970 Evo Plus SSD sitting in a Gen 3 X4 slot but for some reason it's running in X2 after looking at Samsung magician software and have no idea how to make it run in X4 again like it was intended to. My speeds went from been around 3200-3400mb/s read and write to under 1800 read and write and not sure how to fix the problem. Anyone have any suggestions? that would be appreciated!

[Zagna]

The second M.2 slot is just PCIe 3.0 2x from the chipset.

[Flannelist]

If you're only get X2, and it's in the top m.2 slot, i would check in your BIOS for more information, and may allow you to change some settings. Which CPU are you running?