Can't boot LUKS encrypted install after 2023-03-31 stable update

[Uberpanda]

I believe I have the same problem.

Here is a bit more detail :
The update went fine, and was successfully completed.
I have 4 kernels intalled, 4.19, 5.4, 5.15 and 6.1
The first password input show the slot 0 opened as expected.
Grub starts normally, and I can select my OS and kernel
All 4 kernels yield the same error message : “error: no such cryptodisk found”

For 4.19 and 5.4, pressing a key goes to a kernel panic screen :

initramfs unpacking failed: junk in compressed archive
kernel panic - not syncing: VFS: unable to mount root fs on unknown-block(0,0)

initramfs unpacking failed: invalid magic at start of compressed
kernel panic - not syncing: VFS: unable to mount root fs on unknown-block(0,0)

for 4.19 and 5.4, respectively.
For 5.15 and 6.1, the OS then successfully boots.

Running 5.15, I checked dmesg and journalctl for an error, but the initial cryptodisk error is nowhere to be found.
I found, however, this message :

[ 0.059108] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.15-x86_64 root=UUID=b0796842-2403-4e3a-b3b6-7cd0d7151b78 rw i915.enable_guc=2 quiet cryptdevice=UUID=814f0e15-209c-49d8-a680-a4ede7e8aded:luks-814f0e15-209c-49d8-a680-a4ede7e8aded root=/dev/mapper/luks-814f0e15-209c-49d8-a680-a4ede7e8aded
[ 0.059219] Unknown kernel command line parameters “BOOT_IMAGE=/boot/vmlinuz-5.15-x86_64 cryptdevice=UUID=814f0e15-209c-49d8-a680-a4ede7e8aded:luks-814f0e15-209c-49d8-a680-a4ede7e8aded”, will be passed to user space.

This was not present in my previous boot before the update (however, these were on 5.4)

Remediation steps :
From the booted 5.15 :

mkinitcpio -P

No changes

grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro --recheck
grub-mkconfig -o /boot/grub/grub.cfg

This has in fact removed the first cryptodisk error for all 4 kernels. 5.4 and 4.19 are still crashing with the same kernel panic.

mkinitcpio -P

No changes

uninstalling and reinstalling 5.4 from the manjaro-settings kernel application

No changes

EDIT : Solution for this particular problem (kernel panic with older kernels) :

Initramfs unpacking failed: invalid magic as start of compressed

Reinstalling by itself does not suffice. Here is the problem : For some reason, mkinitpcio now creates zstd compressed images instead of the previous default gzip. kernels 5.4 and 4.19 cannot read these images. A workaround is to uncomment COMPRESSION=“gzip” in /etc/mkinitpcio.conf, and rebuild with mkinitcpio -P I am not sure if there is a way to make 5.4 and below able to read zstd.