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/overviewpage.h

@@ -44,7 +44,7 @@ private:
     TransactionFilterProxy *filter;
 
 private slots:
-    void displayUnitChanged();
+    void updateDisplayUnit();
     void handleTransactionClicked(const QModelIndex &index);
 };