I don’t know why - I will of course, try to verify this; I have a laptop for this specific purpose - the first that comes to mind is a change mkinitcpio-openswap.
If you look at the /etc/openswap.conf there is a warning - it is not an old warning - I don’t know when it appeared.
I do suspect that due to this uncertainty around file system integrity there may have been a change somewhere - but I have no clue.
I do know how you can work around though - if interested.
UPDATE:
To be able to input the password for the second disk you will have to press Esc when the plymouth splash screen starts or disable plymouth by editing the cmdline in grub (remove splash and quiet).
As I suspected it is a change in /etc/openswap.conf which default unlock_method=password.
To solve your immediate issue - I understand that you can load your system - entering the passphrase twice - is that correct?
If yes - when system has loaded - edit the file /etc/openswap.conf and buried in between the unlock_method comment and warning comment is the property that causes your issue
## unlock_method can be either password, keyfile or keyfile_raw
## keyfile will use the keyfile_device and keyfile_filename to unlock the swap
## keyfile_raw will use the keyfile_device and keyfile_block_number to unlock the swap
## password will prompt for the password to unlock the swap
## if unlock_method is not set, then method is keyfile if keyfile_device and keyfile_filename are set
## otherwise it is password
unlock_method="password"
####### WARNING: There is a risk of data loss when using unlock_method="keyfile"
## You should double-check keyfile_device_mount_options,
## and note that this method is potentially dangerous regardless.
## https://docs.kernel.org/power/swsusp.html
## https://wiki.archlinux.org/title/Dm-crypt/Swap_encryption#busybox-based_initramfs
Edit the line reading unlock_method="password" to read unlock_method="keyfile", then saved the file and rebuild your init
Be aware that a warning is now present - about the potential disaster - that may come from using keyfile unlocking
-> Running build hook: [openswap]
==> WARNING: you are using potentially dangerous unlock_method keyfile, please make sure you know what you are doing
==> WARNING: https://docs.kernel.org/power/swsusp.html
==> WARNING: https://wiki.archlinux.org/title/Dm-crypt/Swap_encryption#busybox-based_initramfs
mkinitcpio -P
update-grub
I have been aware of the change for some time - I don’t remember any internal discussion.
I thought this was handled by the Calamares framework, if true it is an upstream issue that need to be addressed, but it is also possible that it is Manjaro specific module code that handles it - but I don’t for sure.
I will dig into the matter though.