One of the partitions on a Windows 10 dual boot keeps restarting instead of booting to Windows. How to fix?

[Technique]

So I went ahead with the Windows 10 install but it's gone wrong somehow & i'm wondering how to fix it.

I disconnected ALL drives with the exception of the new 1TB SSD. I booted to the USB stick with Windows 10 on it & accessed the drive for a clean install. 
I then partitioned it off as I wanted and installed Windows 10 to the smaller of the larger of the 2 partitions first (apparently this is called volume 2). It got up & running.
I then booted to the USB stick again, installed Windows 10 to the smaller of the 2 partitions (called volume 3).


Once I had done this I started updating (I didn't have the ethernet cable plugged in initially). While it was updating, I ran cmd to edit bcdedit as per instructions here https://www.top-password.com/blog/windows-10-how-to-change-os-name-in-dual-boot-menu/. My aim was to rename the 2 Windows 10 installs to something more easily identifiable. 
Please let's forget for the purpose of this thread why there's 2x Windows 10 installs on the same drive. I did this with Windows 7 & was told that it could work on Windows 10.

Now when I boot to Volume 3 … the smaller partition, absolutely no problem.
However whenever I boot to Volume 2, the larger partition, the PC restarts again and THEN accesses Windows, so it's basically a really long startup process. I don't get the dual boot screen twice, I only get it once, I select what is Volume 3, the PC just restarts, goes through everything as it would on a normal startup and then accesses the Volume 3 disk … starting that Windows up.

So obviously what I want to know is A) why is it restarting when it shouldn't & also Volume 2 doesn't and B) how do I stop it from restarting? 

 

 

EDIT: If it helps any then I just went in to msconfig and changed the default boot drive and then rebooted. 

After this, the drive that started up perfectly fine beforehand now restarts before eventually booting to Windows and the drive that restarted the PC now actually boots to Windows perfectly fine. 

Edited April 9, 2020 by Technique

[Technique]

Over to you knowledgeable folk as I have tried various ways now.

 

I tried the above and was hoping that it was playing with bcdedit that messed things up so I started again. Sadly that wasn't the case.

 

I tried again without messing with bcdedit - same issue.

 

I tried formatting the SSD to a whole partition, installed Windows 10 to it, went in to disk management, shrunk the volume and then installed Windows 10 to the  newly created volume - same issue.

 

I then tried installing to the SSD as a whole partition, I connected a second HDD and then installed Windows 10 to that drive too - same issue once again. One Windows 10 will start perfectly fine whereas the other will restart the PC and THEN start Windows. 

 

Yet it worked perfectly fine when I did this setup with Windows 7.

 

I'm all out of ideas but there surely has to be a way. Any help you guys?

[Technique]

As i can't edit my post it seems, i will have to post a new post within the thread which will bump it, though that's not my intention as it's pretty much at the top anyway.

 

Just to say that i disabled Windows 10 fast startup on both partitions to see if that would work ... it didn't.