Use this script via
curl -L -O https://gist.github.com/dragon788/e777ba64d373210e4f6306ad40ee0e80/raw/a86f3d05fb56feb6ef01fc2d61a4feb2fd82b281/crypt-fix.sh and
sudo bash ./crypt-fix.sh.
You may need to edit the DEVICE variable to reflect your disk and partition layout (this was created on an EFI system using LUKS and LVM).
It will prompt you for your disk password once to mount and discover the correct name for the encrypted volume mount and
then prompt again to mount with the correct name so that the
update-initramfs command succeeds with the appropriate mapping,
if this wasn't done you would get a warning and your next boot would still fail.