K.D.E. - I just performed a “zypper up” and when I rebooted my menus and choices had changed from English to Spanish (not quite all of them). YaST was undecipherable, the KDE menus very confusing. I managed to navigate to System Settings and they had not been changed from what had previously functioned. It’s not usable as it stands.
That looks ok, so it’s just a user-wide issue within KDE perhaps? If so, find and delete ~/.config/plasma-locale-settings.sh, then restart the session.
Also try to delete ~/.cache/ksycoca* (or the whole ~/.cache directory), this is where KF5 caches the menu entries, including their translation text.
Maybe that cache got corrupted somehow.
Afterwards run kbuildsycoca5 (as user) or logout/login.