AMD X370 itx , install Win10 to AHCI m.2 SSD?

I am using a Ryzen 3 2200G and I have successfully upgraded the BIOS to P4.40 .  

I disabled CSM (compatibility support module) , boot to a UEFI usb stick with Win10 installation on it, and I can choose to install to the Unallocated space on the m.2 SSD (no SATA drives are hooked up).  The SSD drive is a 128gb Samsung AHCI SM951.

The problem is that when the files finish copying to the SSD and the computer reboots, the Windows Boot Loader does not appear and thus I have no way to finish the installation and boot to Windows.  (the only thing I can do is boot to the UEFI USB again, but that just leads to starting over to install Windows , not what I want).

any ideas?  

i am so close to getting this machine up and running (after getting AMD to send me a boot kit so I could flash the BIOS to P4.40) ... but this part is very frustrating!

thanks in advance,

It does seem like if I plug different devices into the USB ports upon booting up the computer it can cause the BIOS to not recognize the Windows Boot Loader and then the system either hangs at the ASRock splash screen or enters the BIOS and I can't see the Windows Boot Loader.  In the past I've reset to BIOS defaults or unplugged the devices and rebooted and can, with a couple of tries, get it to boot to Windows again.  I also tried disabling all the other boot devices except the Windows Boot Loader and the P0 AHCI (the ssd) and maybe that will bring some stability to the boot process.

strange issues, but at least a mostly working system!

i haven't build a system in like 5+ years (I'm back from MacLand) and the complications that booting from PCIe storage devices (like M.2 SSD, etc) along with more complicated and finicky UEFI BIOS programs makes the process more complicated than it was in the past, but then again PCIe storage devices are FAST so once you get going it's worth it!  

i went back to P4.40 to see if the issue occured... it did not after ~15 minutes.  but then i am back to intermittent issues with recognizing the Windows Boot Loader on my SDD.  why the UEFI would recognize the Windows Boot Loader and successfully load Windows sometimes but not others seems especially strange to me.

i may give up on using the M.2 ssd and install Windows to the a SATA ssd.  this should get around the boot issues (but is not what i want :)   if that system runs stable on the P4.40 maybe call it a day?

@stree why do you say that the P4.40 has lots of issues?  it clearly has some boot issues, but I had never seen a Windows 10 blue screen until today on the Beta P4.43...