Have installed Ubuntu Budgie 22.04 for a family member. (Fresh install not an upgrade) Any suggestions on how to change the Keyboard from US English to German? Everything is in German except LibreOffice (User Interface) and the Terminal of course Z = Y. Can’t tweak LibreOffice… US English is locked in. Only Office (User Interface) is in German. Command Line solution? 
Sorry if I’m all over the place… I apologize.
Have uninstalled LibreOffice for Only Office. That problem is solved.
As to the keyboard switching German/English… well, I thought it was over, but it’s back again at a rate of about 50%. There is a lot of advice on the internet dealing with this phenomenon, unfortunately (so far) useless. This happened to me once before when I upgraded from 20.04 to 22.04, but it solved itself with the very next update. This one is a fresh install… which is why I’m puzzled. I don’t have an exotic machine, it’s a LENOVO not a Macintosh. I’ll keep trying (this is the 2nd installation) but I’m starting to think it’s an Ubuntu bug. I don’t want to, but if I can’t solve this I guess I have to go with MINT? My daughter needs her PC. I’ll let you know what happens either way… it should be interesting.
I don’t really understand what issue you are referring to. You mention 50% … of what? What are you actually doing?
Is this thread your issue? Switching keyboard issue - #10 by fossfreedom
Persistence pays off. Problem solved.
1.) Click on IBus Preferences
2.) (Input Method) Add/Remove languages …
in my case I had English and German. I removed English
For libreoffice I suspect you will need at least this package to be installed libreoffice-l10n-de as well as libreoffice-help-de
A FINAL NOTE: IBus - Einstellungen
Compare this Photo (of an older installation) from my other PC German Interface, with the one above English Interface.
My Theory: Apparently… although I selected German, Ubuntu Installer chose to install English version of Ubuntu??? lol 
Confusing? Well… at least it works now.
