Why is new PC hanging on boot?

I'm helping my son set up a new PC - we have an MSI B550 motherboard and Samsung 980 M.2 SSD. Windows 10 install went ok, but when I reboot the PC, it just hangs. I get the BIOS splash screen but it doesn't get any further. If I reset the CMOS, I can boot to the BIOS and check settings - the SSD drive tests ok and is detected as having Windows installed.

I've sent back the SSD and got a replacement, and also tried the other M2 slot on the motherboard. Neither of these things has made a difference.

I'm not sure where to go from here. Are these devices compatible?

Thanks all for your help, but the solution turned out to be that you have to install Samsung Magician before you restart the PC.

It must contain drivers and other stuff that Windows needs to get it working. No idea why it isn't documented anywhere that the drive will not work without it.