Root Key Messed Up

[crimsonmote]

This could be a newbie question so apology ahead, but this is an emergency so any help is much appreciated!

The general situation: I have run a ZFS root on Arch Linux for a long time, and recently decided to change the passphrase prompt at boot to auto loading from a USB stick. I generally follow the wiki from
https://wiki.archlinux.org/title/Install_Arch_Linux_on_ZFS#Loading_password_from_USB-Stick
However, I change the ZFS root passphrase from an explicit passphrase to using a previously created gpg binary key file (base64), and I suppose using a binary key file (that is supposed to be used as a key, not a passphrase, might create the trouble).

Here are some details. I essentially did something like
dd if=/dev/disk/by-id/usb_stick/ROOT bs=32 count=1 | zfs change-key -o keyformat=passphrase zroot/encr
where the file ROOT is the binary key file. Then I followed the rest of the wiki instructions, including modifying the ZFS hook and redo mkinitcpio.
However, on reboot, the key/passphrase is incorrect. I also restarted from a live cd with ZFS support, and cannot load the correct passphrase from the ROOT file. Is there anything can be done to rescue the situation, or is there any other possible cause that I may be missing? Much appreciated.