These strings are coming from the WPLMS theme itself.
I have added the translations.
But it seems like there is some 3rd party cache plugin enabled on your site. SO try disabling them.
Also VIA FTP
go to wp-content/themes/wplms/languages/vibe-de_DE.po and mo
CUT THESE FILES
and PASTE THEM in this folder : wp-content/languages/themes/