modules/javafx.web/src/main/java/javafx/scene/web/HTMLEditorSkin.java

*** 304,314 ****
--- 304,316 ----
                      */
                      if (getCommandState(BULLETS.getCommand()) || getCommandState(NUMBERS.getCommand())) {
                          executeCommand(INDENT.getCommand(), null);
                      }
                      else {
+                         setDesignMode("on");
                          executeCommand(INSERT_TAB.getCommand(), null);
+                         setDesignMode("off");
                      }
                  }
                  else {
                      /*
                      ** if we are in either Bullet or Numbers mode then the
*** 446,456 ****
  
              double totalWork = webView.getEngine().getLoadWorker().getTotalWork();
              if (newValue.doubleValue() == totalWork) {
                  cachedHTMLText = null;
                  Platform.runLater(() -> {
-                     setDesignMode("on");
                      setContentEditable(true);
                      updateToolbarState(true);
                      updateNodeOrientation();
                      executeCommand(STYLEWITHCSS.getCommand(), "true");
                  });
--- 448,457 ----