Question SSD is not being detected on ASRock b450 pro4

[Shahrozjan]

Hello,

I installed a gen 4 WD Black SN 750 SE 500 gb in the ultimate m2_1 NVMe slot but the ssd doesn't show up. I have tried updating bios to 5.0 and in shared SATA3 and SATA4, there is nothing connected. Doesn't show up in UEFI bios menu as well. I have tried changing to m2_2 slot. It still doesn't show up in the disk management. I have set the PCIe x16 and M2_1 speed to gen3 from Auto in advanced configuration inside amd pbs too. Is there some setting that I might be missing? Also, the motherboard has PCIe express 3.0 but i heard that gen 4 ssds will work on it.

Specs
Mob: ASRock B450 pro4
CPU: AMD Ryzen 5 3600
Bios: P5.0
OS: Windows 10 64 bit

 

[Enrique Sanchez]

Have you tried to disable Secure Boot and then after rebooting - enable CSM? Boot after each action (twice)

 

[Shahrozjan]

Have you tried to disable Secure Boot and then after rebooting - enable CSM? Boot after each action (twice)

Tried, didn't work. Also contacted ASRock meanwhile and they said that

SN750 SE, this is GEN 4 version.
The SN750 is GEN 3 version and it can be supported by B450 Pro4

After doing many test, we confirm that SN750 SE is not compatible with B450 Pro4 and we recommend choosing the SSD which is listed on the QVL.

This is weird because the ssd specifically states that it is backwards compatible on gen 3 PCIe. I am wondering where the problem lies. Possibly in the ASRock bios.
Also, my bios was on P3.60
Someone told me to update and I went
3.60->4.20->5.00