System Drive Encryption issues

[WRVC2016]

Usually, I do a "system partition" encryption. Today, I decided to do a "system drive" encryption. It went through the pretest fine. However, when it was done encrypting, I rebooted and was not able to get pass the VeraCrypt password screen. It kept saying error out.

So I popped that drive into another computer that has VeraCrypt. I was not able to log into the drive until I finally realized to use the "Mount Without Pre-Boot Authentication". It worked and mounted to a drive letter. I was then able to access my "VeraCrypt Rescue Disk.iso" on that drive. I decided to give the drive another try, by booting in with the "VeraCrypt Rescue Disk". It worked! I then took the "VeraCrypt Rescue Disk" out and rebooted again. This time, it also worked even without the "VeraCrypt Rescue Disk".

Upon looking at the system properties, it said that it is a "system drive" encryption.

1. So what happened here where it would not take my password and pin the first time?
2. What fixed it? Was it the "VeraCrypt Rescue Disk" or was it the "Mount Without Pre-Boot Authentication"
3. Also, does the "system drive" encryption offer any better protection compared to the "system partition" encryption?

[WRVC2016]

On my second attempt of doing a FULL DRIVE ENCRYPTION of the OS was successful. I am not sure if it is because one of the following?

• Installed (VeraCrypt_Setup_x64_1.26.7.msi) instead of (VeraCrypt Setup 1.26.7.exe).
• Did not select "YES" for "Encryption of Host Protected Area". Selected "No".
• Used a different SSD.

It did not give the same issue as the above which I was hoping to replicate to understand why it failed.