Question m.2 drive worked in the second slot but the the first

[frogpuppy]

Hi,
I have an Asrock z490 extreme motherboard (You can check the manual for the MB from here) and as you can see the mb has 3 m2 slots called m2_1, m2_2 and m2_3.
Also as stated in the manual (Page35) the m2_2 if enabled, will disable SATA3_1 and if m2_3 is enabled the SATA3_5 will be disabled.

Got my m.2 drive yesterday and installed it in the first m2 slot (M2_1) because it won't disable any SATA drive but the drive didn't work (not detected in disk management or bios)
So I take it off and installed in the m2_2 slot and it worked without disabling the SATA drive that's connected to SATA3_1 slot.

I have two questions.
First, why the drive didn't work in the m2_1 slot?
Second, why it didn't disable the sata slot as stated in the manual?

I'm asking those questions just to help understand what actually happen. Also to know what to do in future if I want install another m.2 drive.

 

[Mr.Spock]

that slot supports NVMe - not SATA, from the manual pg 32.
you didn't mention what model of SSD you're using?

2.10 M.2_SSD (NGFF) Module Installation Guide (M2_1) The M.2, also known as the Next Generation Form Factor (NGFF), is a small size and versatile card edge connector that aims to replace mPCIe and mSATA. The Hyper M.2 Sockets (M2_1) supports M Key type 2260/2280 M.2 PCI Express module

 

[frogpuppy]

that slot supports NVMe - not SATA, from the manual pg 32.
you didn't mention what model of SSD you're using?

2.10 M.2_SSD (NGFF) Module Installation Guide (M2_1) The M.2, also known as the Next Generation Form Factor (NGFF), is a small size and versatile card edge connector that aims to replace mPCIe and mSATA. The Hyper M.2 Sockets (M2_1) supports M Key type 2260/2280 M.2 PCI Express module

Sorry for not mentioning that. I'm using a samsung 970 plus which is an nmve
https://www.amazon.com/gp/product/B07MFZXR1B

 

[frogpuppy]

So the m.2_2 didn't disable the sata slot because the drive is an nvme and not a sata drive.

But I still don't know why the first m.2 slot didn't work. Anyone got any idea?