Z790 I M.2_2 not showing in BIOS

[ThyNightKing]

I am trying to install 2 Samsung pro PCIe 4.0 990 NVMe m.2 ssds in to my new system. I am currently scratching my head and wondering if I have missed something. I have tried loads of different things and can’t get it to work. The M.2_2 slot is not showing in the BIOS. 
Both ssds work as I have tested in different systems as a troubleshoot. I have reseated both drives and seated correctly. 

My system specs are as followed-

-ROG STRIX Z790-I Gaming WiFi
-Intel Core i7-14700k
-2x16GB DDR5 (6400 MHz) 
-2 x 2TB Samsung Pro PCIe 4.0 NVMe M.2
-ROG STRIX RTX 2070 (Temp) 
(waiting for 5070ti to be delivered) 

please can someone advise on how to fix the M.2_2 Slot visibility problem?

[Jiaszzz_ROG]

Hello @ThyNightKing 

Thank you for reaching out to us.
Could you please confirm your current BIOS version? Have you updated to the latest version 2801 and cleared CMOS?
Have you tried installing a single SSD in the M.2_2 slot or swapping the SSDs between the two slots to check if the issue is related to a specific SSD not being recognized?
Please also refer to [Motherboard] Troubleshooting - Cannot find the hard disk drive or SSD (M.2) after motherboard power... for further guidance and adjust the BIOS settings accordingly to see if there are any changes.

Thank you.