sddm revert to default theme and kde_settings.conf don't work

[Sharaf5]

Tring to set sddm via systemsettings5 or systemsettings reverted the theme to the default one
digging files and docs I played around the systemsettings GUI while watching files ( I have only two ) :

• /etc/sddm.conf.d/kde_settings.conf
• /etc/sddm.conf

First file is always modified by systemsettings but somehow sddm don't see these changes and revert to default theme
I edited the second one with the same configrations but no change
once I deleted the first file all thing go as expected

• System : Ubuntu 22.04.4 LTS jammy
• Upgrades : before a week
• systemsettings Last success : before 3 days
• File permisions : never changed by user