The text "Search..." inside the search box of the applet is not translated to the language of the desktop.
STEPS TO REPRODUCE
1. Open network applet
2. Press the magnifying glass icon
Grey text "Search..." inside the search box is in English
Translated grey text e.g. "Suchen..." in German.
Linux/KDE Plasma: Arch Linux stable kernel 5.4.6
(available in About System)
KDE Plasma Version: 5.17.4
KDE Frameworks Version: 5.65.0
Qt Version: 5.14.0
*** This bug has been marked as a duplicate of bug 413900 ***