I'm totally at lost.
There was a sales near where I live. So I bought "Seagate Exos X18 18 TB 3.5" 7200 RPM".
I connect it to my power supply / mother board and here come the issue.
This bad boy does not spin, so I can't see it in the bios.
I was like, okay, probably a faulty one. Before bringing it back to the retailers. I tried it in an external hard drive enclosure and there it start spinning, I can see it in windows, everything fine.
I tried updating the bios firmware.
Plugging it on a sata cable already used by another hard drive so I know the sata cable is not faulty.
Reusing a power cable already used by another drive.
Unplugging all the hard drive except this one , leaving it with the two m2.
So I was like, maybe it's not my job ? Maybe I should admit that I'm not as tech savy as I tought so
I went back to the retailers with my desktop and he told me some stuff about "oh you got two m2 drive ? you should unplug one". My naive self was like "what ? How

? Well maybe he know more than me".
I went back home and guess what, nothing changed, except I have one m2 unplugged on my desk.
And suddently it hit me, but why it doesn't spin ? Even without the data cable it should spin? Am I crazy ?
Here some link :
https://pcpartpicker.com/list/bHBht7 PcPartPicker build that say everything is compatible (yeah I'm naive)
Some picture cause why not :
https://imgur.com/a/rnymOql