No crypto user for encrypted APFS volume!

After an update to High Sierra, I'm trying to unlock my volume (disk1s1) but cannot anymore. This is the info from terminal:

APFS Container (1 found)
|
+-- Container disk1 C8022E32-744D-414E-9246-29ADDB0357F3
    ====================================================
    APFS Container Reference:     disk1
    Size (Capacity Ceiling):      500068036608 B (500.1 GB)
    Minimum Size:                 500068036608 B (500.1 GB)
    Capacity In Use By Volumes:   485282820096 B (485.3 GB) (97.0% used)
    Capacity Not Allocated:       14785216512 B (14.8 GB) (3.0% free)
    |
    +-< Physical Store disk0s2 438AD64B-835E-418D-B0DF-32A3A0B7500A
    |   -----------------------------------------------------------
    |   APFS Physical Store Disk:   disk0s2
    |   Size:                       500068036608 B (500.1 GB)
    |
    +-> Volume disk1s1 6C587DE6-9C8D-3792-9144-34FBE59AE9F6
    |   ---------------------------------------------------
    |   APFS Volume Disk (Role):   disk1s1 (No specific role)
    |   Name:                      Macintosh HD (Case-insensitive)
    |   Mount Point:               Not Mounted
    |   Capacity Consumed:         382597644288 B (382.6 GB)
    |   FileVault:                 Yes (Locked)
    |
    +-> Volume disk1s2 B7508926-2601-4C8D-9707-5F53EA943031
    |   ---------------------------------------------------
    |   APFS Volume Disk (Role):   disk1s2 (Preboot)
    |   Name:                      Preboot (Case-insensitive)
    |   Mount Point:               Not Mounted
    |   Capacity Consumed:         39792640 B (39.8 MB)
    |   FileVault:                 No
    |
    +-> Volume disk1s3 51B76A93-806E-474D-9BBA-F1E752C3032B
    |   ---------------------------------------------------
    |   APFS Volume Disk (Role):   disk1s3 (Recovery)
    |   Name:                      Recovery (Case-insensitive)
    |   Mount Point:               Not Mounted
    |   Capacity Consumed:         1038880768 B (1.0 GB)
    |   FileVault:                 No
    |
    +-> Volume disk1s4 A680E59F-DF9D-4354-BE1E-6A8AA71390A5
    |   ---------------------------------------------------
    |   APFS Volume Disk (Role):   disk1s4 (VM)
    |   Name:                      VM (Case-insensitive)
    |   Mount Point:               /private/var/vm
    |   Capacity Consumed:         4295213056 B (4.3 GB)
    |   FileVault:                 No
    |
    +-> Volume disk1s5 7683ED91-DACF-4213-8C73-F2C24518A4B2
        ---------------------------------------------------
        APFS Volume Disk (Role):   disk1s5 (No specific role)
        Name:                      Macintosh HD2 (Case-insensitive)
        Mount Point:               /
        Capacity Consumed:         97149804544 B (97.1 GB)
        FileVault:                 Yes (Unlocked)

Notice after a failed upgrade, I had to partition the drive to install a fresh OS (Macintosh HD2) to move on with my life, in hopes one day I can access my original volume. Now I'm trying to unlock the original Macintosh HD / disk1s1, but its crypto users disappeared (they were there before)!

diskutil apfs listUsers disk1s1
No cryptographic users for disk1s1

I tried entering a blank password but not luck:

diskutil apfs unlockVolume disk1s1 -nomount
Passphrase:
Passphrase entry error: no passphrase specified

Entering my old password or a space as the password gives this:

diskutil apfs unlockVolume disk1s1 -nomount
Passphrase:
Unlocking any cryptographic user on APFS Volume disk1s1
Unlocked but did not mount APFS Volume

But it really doesn't unlock it:

diskutil apfs list
    +-< Physical Store disk0s2 438AD64B-835E-418D-B0DF-32A3A0B7500A
    |   -----------------------------------------------------------
    |   APFS Physical Store Disk:   disk0s2
    |   Size:                       500068036608 B (500.1 GB)
    |
    +-> Volume disk1s1 6C587DE6-9C8D-3792-9144-34FBE59AE9F6
    |   ---------------------------------------------------
    |   APFS Volume Disk (Role):   disk1s1 (No specific role)
    |   Name:                      Macintosh HD (Case-insensitive)
    |   Mount Point:               Not Mounted
    |   Capacity Consumed:         382597644288 B (382.6 GB)
    |   FileVault:                 Yes (Locked)

I tried decrypting it as well, but no luck (entered my password used before the update, also tried space as password):

diskutil apfs decryptVolume disk1s1
Passphrase for existing "Disk" user 6C587DE6-9C8D-3792-9144-34FBE59AE9F:
Starting background decryption of disk1s1 using the "Disk" crypto user as authorization
Error starting background decryption of APFS Volume: One or more of the given or implied APFS Volumes are locked (-69582)

Which is strange it's asking for a users passphrase when it told me there were no users; even stranger that this user's ID is the same as the volume disk ID. So I tried reseting the passphrase for this user:

diskutil apfs changePassphrase disk1s1 -user 6C587DE6-9C8D-3792-9144-34FBE59AE9F6
Old passphrase for user 6C587DE6-9C8D-3792-9144-34FBE59AE9F6:
New passphrase:
Repeat new passphrase:
Changing passphrase for cryptographic user 6C587DE6-9C8D-3792-9144-34FBE59AE9F6 on APFS Volume disk1s1
Error changing passphrase for cryptographic user on APFS Volume: The crypto user was not found on the APFS Volume (-69594)

Any help on how to recover from this dreadful state, such as adding crypto users back? Thanks for any help!