So, the key point is succeed in chrooting.
I’m sorry I never had to use encrypted linux (only personal use at home…), so cannot provide real assistance.
How do you decrypt normally? Try with the CLI instead of GUI tools.
If you do something like:
sudo cryptsetup open /dev/nvme0n1p2 crypto_LUKS
That crypto_LUKS should be used (or whatever the name you use).
You could try:
sudo mount /dev/mapper/crypto_LUKS /mnt/broken
(or the different name used), but you could try also:
sudo mount -o subvol=@ /dev/mapper/crypto_LUKS /mnt/broken
I also just remembered a very long topic where arch-chroot worked instead of garuda-chroot:
You could give it a try. Just change the luks-xxx data with yours and sudo mount /dev/nvme0n1p1 /mnt/boot/efi
.