add the slot updateDisplayUnit() to overviewpage, sendcoinsdialog, sendcoinsentry and connect it to displayUnitChanged() - this ensures all fields in the GUI, who use a display unit are imediately updated, when the user changes this setting in the optionsdialog / ensure used fields init with the current set display unit

src/qt/sendcoinsdialog.h

@@ -47,8 +47,8 @@ private:
 
 private slots:
     void on_sendButton_clicked();
-
     void removeEntry(SendCoinsEntry* entry);
+    void updateDisplayUnit();
 };
 
 #endif // SENDCOINSDIALOG_H