B550-A Pro M2_1 Slot not working?

Onboard m2 slot or pcie m2 expantion card? which is faster? m 2 pcie slot The motherboard slot #2 shares bandwidth with several PCIe expansion slots When the slot is populated with a PCIe drive, four PCIe expansion m2 expansion slot Drives that use NVMe were introduced in 2013 to attach to the Peripheral Component Interconnect Express slot directly on a motherboard

m2 pcie slot Does it matter which SSD slot I use