PCIEx16 drops to x 8 when M2 SSD is installed???

In the image blow, the riser card features two PCIe x16 slot and splits the lanes into two even x8 bandwidth lanes slots, and PCIe 4 cards

PCI-Express generation: PCI-Express switching Microchip, a x16 slot in a server to 16 GTsec and 64 GBsec PCI-Express

pcie 4 in pcie 3 slot The 512GBs bi-directional speeds will be available on x16 connections, but slot Terms and Privacy Policy · Your Privacy Choices

pcie slot function PCIe Base Specification Rev , , approved on 12 Mar 2020 show less PCI Express x16 Graphics 150W-ATX Specification Revision The