Hello, > Which font are you using please ? I am using Hack 9pt. To clarify, I do not see the umlaute shifted that extremely as you can see at https://bugsfiles.kde.org/attachment.cgi?id=109581, but rather similarly to https://bugsfiles.kde.org/attachment.cgi?id=133560 (in the substring "mac-Ö_ü_ä-test"). I use Debian Bookworm. This affects both Konsole and Kate.
Best, Samuel Plavec
