Question M.2_1 NVMe slot no longer present (in BIOS / OS)

[fullofclovers]

Booted my newly built PC (built in December 2020) up today and realized I'm missing one of my NVME drives when I could no longer post from my OS installed on the M.2_1 slot. For some reason, the M.2_1 slot is no longer functioning. M.2_2 is still working. I've had this system running fine using both NVMe slots up until today.

My Setup:
Mobo: MSI MAG B550 Tomahawk
Mem: 16gb Trident Z @3600mhz
GPU: RTX 3070
CPU: AMD Ryzen 5800x
Storage: Samsung 970 EVO 500gb NVMe (OS installed to M.2_1) / Samsung 970 EVO 1tb NVMe (installed to M.2_2) / WD 1tb SSD
PSU: Corsair RMX 750w

What I've tried so far:

• Swapped NVMe drives to M.2_2 and ensuring it wasn't a case of bad storage.
• Updated BIOS to latest
• Reset CMOS

Having my OS now on M.2_2, I can load into Windows just fine. I'm just baffled what happened seemingly in the middle of the night to cause my M.2_1 slot to no longer function.

Anyone have a clue as to what is going on here? I'd hate to RMA this board right now.

 

[SkyNetRising]

AMD Ryzen 5800x was not yet released in October 2020.
Did you have some other cpu first and then change it?

 

[fullofclovers]

AMD Ryzen 5800x was not yet released in October 2020.
Did you have some other cpu first and then change it?

D'oh! I meant to say "Built in December 2020". You'll have to forgive my brain fog. I've been working from home for close to a year now. I'll edit my post with the correct date.