SDDM do not use system locales on Hyprland image.

[izdener]

SDDM doesn't pick up the system locale settings for keyboard layout.

[RoyalOughtness]

After looking into this a bit, I think this might be a bug in the sddm-wayland-generic subpackage of Fedora's sddm package. The sddm-wayland-sway subpackage pulls in a custom config that executes a sway-provided executable to pull system locales. This works in part I assume because SDDM itself is running on sway, whereas the sddm-wayland-generic package runs using weston.

So a solution to this from the wayblue side could be to switch all images to sddm-wayland-sway, but that would pull sway in to all the images: https://src.fedoraproject.org/rpms/sway-config-fedora/blob/rawhide/f/sway-config-fedora.spec#_65

So I would recommend creating an upstream bug on this, here: https://bugzilla.redhat.com/buglist.cgi?bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&component=sway-config-fedora&product=Fedora&query_format=advanced