Problem with encrypting /boot

After installing Kali (i selected full disk encryption during the installation), i'm trying so hard to encrypt my /boot partition but i fail everytime.

What i do is:
mount --bind / /mnt/
cp -a /boot/* /mnt/boot/
cp -a /boot/vmlinuz-* /mnt/boot/
diff -ur /boot/ /mnt/boot/
umount /mnt/
nano /etc/fstab (i remove the 10th line with the UUID /boot ext2 etc)
I make a backup of my current boot cp /boot/grub/grub.cfg /boot/grub/grub.cfg.backup
grub-mkconfig > /boot/grub/grub.cfg
i reinstalled grub loader with echo GRUB_ENABLE_CRYPTODISK=y >> /etc/default/grub
grub-install /dev/sda

I didn't received any type of errors during the procedure

Then i reboot and it doesn't ask for a password when i boot to grub

Am i missing something?

Thanks a lot!

Version: 2018.1 64bit
Laptop: Dell Inspiron 5570

CRITICAL ERROR decrypting windows 7 bitlocker using dislocker v0.7.1

Guys please help me out I have successfully installed dislocker v0.7.1 on my kali 2017.1. I used the following command
dislocker -v -V /dev/sda5 -uPASSWORD (/dev/sda5 is my windows7 partition encrypted using bitlocker)
to try and decrypt the bitlocker but this is the output I got

sat Mar 24 17:44:31 2018 [ERROR] The MACs don't match.
Sat Mar 24 17:44:31 2018 [ERROR] Can't decrypt correctly the VMK. Abort.
Sat Mar 24 17:44:31 2018 [CRITICAL] None of the provided decryption mean is decrypting the keys. Abort.
Sat Mar 24 17:44:31 2018 [CRITICAL] Unable to grab VMK or FVEK. Abort.

I have google everywhere to find a solution but no luck.
CAN PLEASE SOMEBODY HELP ME OUT!
THANKS.