RZ09-0409BEC3 - Second M.2 SSD are 5.0 SSDs not Compatible

I own a RZ09-0409BEC3 (Razer Blade 15 2021 Model) and I was looking to expand my storage through the use of the second M.2 NVMe slot - my understanding (which is limited) based on research is the the slots are backwards compatible but would just limit a SSD to the slots gen speeds. So Gen 4 will work in a Gen 3 slot but at Gen 3 speeds, etc. I recently brought a Samsung 9100 PRO PCIe 5.0 x 4 NVMe M.2 SSD since I might be upgrading in the future and it’s not appearing in BIOs or Windows Disk Manager. Can you confirm if a 5th Gen SSD is compatible and if not what is the make Gen I can use?