How get ubuntu to boot after reducing size of encrypted logical volume?

After reducing the size of /root volume of an encrypted partition using lvm, I get this error when ubuntu boots:

cryptsetup: cryptsetup failed, bad password or options

The partition itself is fine. I can open the encrypted container, and mount and browse the file system, if I go in manually from a live usb.

I reduced the size of root using the steps given in these guides:

https://ubuntuforums.org/showthread.php?t=726724
https://help.ubuntu.com/community/ResizeEncryptedPartitions
https://askubuntu.com/questions/262211/how-do-i-resize-an-encrypted-lvm-to-install-another-copy-of-ubuntu

Since the resize did actually work, it is not strictly necessary to show what steps I took to do the resize. But I replicate them here for assurance, and the possibility that they are the source of the error.

(I also renamed the logical volume group, for ease of typing, from ubuntu-studio-vg to sys-vg).

Steps I took to reduce the volume size were as follows:

sudo cryptsetup luksOpen /dev/sda5 bonse
sudo e2fsck -f /dev/mapper/sys--vg-root
sudo resize2fs -p /dev/mapper/sys--vg-root 150G
sudo e2fsck -f /dev/mapper/sys--vg-root
sudo lvreduce -L 150.1G /dev/sys-vg/root
sudo lvremove /dev/sys-vg/swap_1
sudo pvresize --setphysicalvolumesize 158.2G /dev/mapper/bonse
sudo lvcreate -L 8G -n swap_1 sys-vg
sudo mkswap -L swap_1 /dev/sys-vg/swap_1
sudo mount /dev/sys-vg/root /mnt
sudo umount /mnt
sudo pvchange -c n /dev/mapper/bonse
sudo cryptsetup status bonse

Last statement gives:

...offset: 4096 sectors ...size: 624136192 sectors

Then:

sudo cryptsetup resize --size 309082032 bonse
sudo vgchange -an
sudo cryptsetup luksClose bonse
sudo fdisk /dev/sda

In fdisk:

• deleted sda5 and sda2
• created new sda2 as an extended partition: size +159G
• created new sda2 as an extended partition: size +159G
• created new sda5 as an extended partition: size +158.9G
• changed sda5 partition type to '8e: linux LVM'

Finally, edited /mnt/etc/fstab mousepad, initially replacing the root and swap devices so that references to ubuntu--studio--vg were replaced with sys--vg. But this didn't work. So I changed the device references to UUID=< and used the LV UUID given for each volume by lvdisplay >.

The result, to recap, was error on boot. But still able to open, mount and read the drive manually.