Hi!  I reproduced this problem using Debian Live 13.3.0 gnome image,
selecting 'Start Installer' at the boot prompt, doing a Swedish locale
install using automatic disk partitioning.  Everything installs fine,
but on first login the GNOME keyboard layout is set to 'Japanese (Mozc)'
in the upper right keyboard input menu.

I don't know how that keyboard layout is supposed to work, because the
keyboard behave just like a Swedish keyboard layout, so at first I never
notice anything was wrong because the keyboard worked fine.  Maybe this
is how it is supposed to work.  Selecting the second-preferred
alternative 'Swedish' doesn't seem to modify any for the keyboard, but
looks more correct.  Removing the 'Japaneze (Mozc)' layout makes the
keyboard input menu go away, which is what I'm used to.

I'm attaching a screenshot so you can understand which menu I refer to.

/Simon

PS.  I recall seeing this for Calamares-based installs from the running
live GNOME session too, but I'm not 100% and did not reproduce it for
this bug report.

block 1125415 by 1144959
thanks

Thanks for the report and proposed fix to ibuz-mozc!

Compare my earlier report: https://bugs.debian.org/1125415

I believe the #1125415 problem still occurs using official Debian 13.7
Live ISO images and selecting a Swedish locale.

I can confirm that applying the #1144959 patch in a custom-built Live
ISO no longer results in 'Japaneze (Mozc)' as the selected keyboard
layout, when using a Swedish locale.

/Simon