USB Persistence with LUKS Encryption - Not so persistant

I have followed the documentation to create a Live USB w LUKS , although it is not persistant .

I have the persistence.conf on /dev/sdb3 with " / union " in the file.

My partition table

Code:

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Disk /dev/sdb: 15.1 GiB, 16231956480 bytes, 31703040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x0a9a1b1a

Device    Boot  Start      End  Sectors  Size Id Type
/dev/sdb1  *        64  6324223  6324160    3G 17 Hidden HPFS/NTFS
/dev/sdb2      6324224  6485375  161152 78.7M  1 FAT12
/dev/sdb3      6486016 31703039 25217024  12G 83 Linux

Disk /dev/loop0: 2.8 GiB, 2969686016 bytes, 5800168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/luks-33454b89-9c87-44a5-a2f7-9903854667f2: 12 GiB, 12909019136 bytes, 25212928 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

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What Am I Missing?

( I choose the persistant option at boot )