Problem after detaching the header

Hi

I am trying to move my current included header from sda2 to a separate raw (no file system) partition of device sdb1, but after removing the original header the system does not start and stops at the initramfs console.

OS: LMDE 5 (Linux Mint Debian Edition = de facto Debian 11)
Standard LVM installation on LUKS2

I did the following steps:
1. cryptsetup luksHeaderBackup /dev/sda2 --header-backup-file /header.img
2. dd if=/header.img of=/dev/sdb1
3. option luks,discard,tries=3,header=/dev/sdb1 > /etc/crypttab
4. update-initramfs -u -k all
5. cryptsetup luksErase /dev/sda2

Up to this point, everything works fine and the system boots up properly
When, according to the instructions in the https://gitlab.com/cryptsetup/cryptsetup/-/blob/main/FAQ.md I do:
6. cryptsetup luksDump /dev/sdb1 > Data segments: offfset: 16777216 bytes
7. dd bs=512 count=32768 if=/dev/zero of=/dev/sda2
the system no longer starts.

Have I screwed something up or am I missing a step?
Please help!

Darek