Attempt at some QT fixes.

src/qt/qt_mainwindow.cpp

@@ -1594,7 +1594,11 @@ void MainWindow::keyPressEvent(QKeyEvent* event)
 void MainWindow::blitToWidget(int x, int y, int w, int h, int monitor_index)
 {
     if (monitor_index >= 1) {
+#ifdef STRICTER_CHECK
         if (renderers[monitor_index] && renderers[monitor_index]->isVisible()) renderers[monitor_index]->blit(x, y, w, h);
+#else
+        if (renderers[monitor_index]) renderers[monitor_index]->blit(x, y, w, h);
+#endif
         else video_blit_complete_monitor(monitor_index);
     }
     else ui->stackedWidget->blit(x, y, w, h);
@@ -2053,6 +2057,8 @@ void MainWindow::on_actionShow_non_primary_monitors_triggered()
 {
     show_second_monitors ^= 1;
 
+    blitDummied = true;
+
     if (show_second_monitors) {
         for (int monitor_index = 1; monitor_index < MONITORS_NUM; monitor_index++) {
             auto& secondaryRenderer = renderers[monitor_index];
@@ -2079,5 +2085,7 @@ void MainWindow::on_actionShow_non_primary_monitors_triggered()
             }
         }
     }
+
+    blitDummied = false;
 }