Unable to use 2nd NVME SSD

Unfortunately yes But, first, NVMe is not slot, it is a communication standard Slot used for NVMe based SSDs in consumer market is called M

NVMe port, opening up the possibility of using lightning-fast NVMe SSDs on your system

which expansion slot is used by an nvme compliant device_ NVMe PCIe® x4 & PCIe® x2 • 1x PCIe ® Slot 2 2280 • NVMe PCIe x4 and SATA Mode 12 Smart Fan 5 + FAN STOP • 3 Fan

which slot If not, you can still use a NVME SSD for storage by using an adapter card to place it in a regular PCIe slot However you will probably not