After having installed Manjaro with Swedish language settings I noticed that Manjaro was very stable. Program menu was in swedish and everything was ok.
I swiched to testing branch and got more than 300 updates. Everything then was upside down. The language set is now a mix of english and swedish in the program menu.
You can’t no longer in “Regional settings - Language - Configure Plasma translations” choose Swedish. It’s not longer there.
Thank you for the advice.
Did you get an answer to your question?
I have the same problem with not being able to choose Swedish, and I think it happened after the last update.