I have a fresh install (today) for latest EOS with Gnome.
I am using two keyboards with one keymap en_UK and another fr_Latin9. I do a full disk encryption at fresh install. I learnt that the password is going to be en_UTF8 (for the disk encryption) regardless of the keymap set at install. It does not bother me much. The real issue is after. Fresh install finish and reboot. I am then ask to type in the password for disk encryption. I use an external keyboard K780 with a dongle. This is the one with keymap en_UK. I type in the password in us_UTF8 but no go. Encryption password is not accepted. I type in the same password on my internal keyboard (laptop Delta 15 AMD) and I am in. Keep in mind that the keymap on this laptop is (fr_latin9). When I typed in the password to encrypt the disk, I did it once with the internal keyboard and once with the external keyboard.
I followed the arch wiki saying put “keyboard and keymap” before autodetect in mkinitcpio (hooks). Still a no go.
I am blanking out. What could be the pb ? I would like to be able to decrypt my drive with my external keyboard.
I think it’s a good idea to restrict your password to ASCII characters (from 32 to 127).
I do.
As of today, I have tested a lot of distribution with the basic install. BTRFS/LUKS and all have the same issue. Arch, EOS, ARCO. Same keyboard and same password. The only one that does not cause the pb is Fedora 36. My external keyboard (logitech) works when typing in the password to decrypto the full disk encryption using BTRFS.
I have a feeling this one is going to be a mistery 
Yeah, seems that way to me, too… It has all the elements of a good mystery. 
Have a look at the following thread and see if there is any similarity to your issue:
and I am not the only one. The internet reports same symptoms as me. Apparently different root cause since.
This is as per the tip at the mkinitcpio wiki’s section on common hooks:
Tip: For systems that are booted with different hardware configurations (e.g. laptops with external keyboard vs. internal keyboard or headless systems), it is helpful to place this hook before autodetect in order to always include all keyboard drivers. Otherwise the external keyboard only works in early userspace if it was connected when creating the image.
what is really weird to me, is why a fr keymap can be accepted by luks (with en_UTF8 password) and not a uk keymap. The logitech keyboard has a dongle for the bluetooth connection. Could that be the culprit ? Probably not because if that was the case even Fedora would not work and it works. The difference that Fedora has with the rest is that its not full disk partition.
Even tried adding the driver below. Then got boot to a black screen. Had to use external system to correct the mistake.
MODULES=(atkbd)
Sometimes its just a matter of time
Same as my keyboard backlit for the MSI delta 15 !! The solution miraculously appears usually when I stop searching.
Its not a show stopper. The internal keyboard of the MSI laptop can easily decrypt the ssd. I am afraid, though, if that keyboard does not work anymore, I will be stuck.
@pebcak
System Locale: LANG=en_US.UTF-8
VC Keymap: uk
X11 Layout: gb
Its not making any sense. The French (fr_latin9) can luks with en_us_UTF8 password but not the uk keymap. I could be wrong but I don’t think changing the VC keymap is going to make any difference here.
You want to know something funny !!
Further down the rabbit hole of “full disk encryption”. I created another key file (another slot) for luks.
I used the external keyboard (uk) to type in the same passphrase. Added the key to initrd. Rebooted. I am now asked by grub to decrypt my ssd. I, still, am unable to decrypt the luks ssd with external keyboard. I use the internal for that slot. Then comes the second slot (keyfile added by me today). If I use the external UK keyboard, it works perfectly fine and I am in…
This is a mistery !!!
Finally decided to give up on full disk encryption. I read a post that basically made me understood that full disk encryption is way above my paygrade. I am merely a user of Linux EOS and that’s all. I did learnt a lot though.
Without full disk encryption, my rig is much more responsive and fans ramping up a lot less (silver lining)