diff --git a/src/qt/qt_mainwindow.cpp b/src/qt/qt_mainwindow.cpp
index 2a0a561e9..0a13e1bfb 100644
--- a/src/qt/qt_mainwindow.cpp
+++ b/src/qt/qt_mainwindow.cpp
@@ -315,27 +315,32 @@ MainWindow::MainWindow(QWidget *parent) :
 
     connect(actGroup, &QActionGroup::triggered, [this](QAction* action) {
         vid_api = action->property("vid_api").toInt();
+        RendererStack::Renderer newVidApi = RendererStack::Renderer::Software;
         switch (vid_api)
         {
         case 0:
-            ui->stackedWidget->switchRenderer(RendererStack::Renderer::Software);
+            newVidApi = RendererStack::Renderer::Software;
             break;
         case 1:
-            ui->stackedWidget->switchRenderer(RendererStack::Renderer::OpenGL);
+            newVidApi = (RendererStack::Renderer::OpenGL);
             break;
         case 2:
-            ui->stackedWidget->switchRenderer(RendererStack::Renderer::OpenGLES);
+            newVidApi = (RendererStack::Renderer::OpenGLES);
             break;
         case 3:
-            ui->stackedWidget->switchRenderer(RendererStack::Renderer::OpenGL3);
+            newVidApi = (RendererStack::Renderer::OpenGL3);
             break;
         case 4:
-            ui->stackedWidget->switchRenderer(RendererStack::Renderer::Vulkan);
+            newVidApi = (RendererStack::Renderer::Vulkan);
             break;
         case 5:
-            ui->stackedWidget->switchRenderer(RendererStack::Renderer::Direct3D9);
+            newVidApi = (RendererStack::Renderer::Direct3D9);
             break;
         }
+        ui->stackedWidget->switchRenderer(newVidApi);
+        for (int i = 1; i < MONITORS_NUM; i++) {
+            if (renderers[i]) renderers[i]->switchRenderer(newVidApi);
+        }
     });
 
     connect(ui->stackedWidget, &RendererStack::rendererChanged, [this]() {
@@ -1579,16 +1584,36 @@ void MainWindow::on_actionResizable_window_triggered(bool checked) {
         setWindowFlag(Qt::WindowMaximizeButtonHint);
         setWindowFlag(Qt::MSWindowsFixedSizeDialogHint, false);
         setFixedSize(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX);
+        for (int i = 1; i < MONITORS_NUM; i++) {
+            if (monitors[i].target_buffer) {
+                renderers[i]->setWindowFlag(Qt::WindowMaximizeButtonHint);
+                renderers[i]->setWindowFlag(Qt::MSWindowsFixedSizeDialogHint, false);
+                renderers[i]->setFixedSize(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX);
+            }
+        }
     } else {
         vid_resize = 0;
         setWindowFlag(Qt::WindowMaximizeButtonHint, false);
         setWindowFlag(Qt::MSWindowsFixedSizeDialogHint);
+        for (int i = 1; i < MONITORS_NUM; i++) {
+            if (monitors[i].target_buffer) {
+                renderers[i]->setWindowFlag(Qt::WindowMaximizeButtonHint);
+                renderers[i]->setWindowFlag(Qt::MSWindowsFixedSizeDialogHint, false);
+                emit resizeContentsMonitor(monitors[i].mon_scrnsz_x, monitors[i].mon_scrnsz_y, i);
+            }
+        }
     }
     show();
-    ui->stackedWidget->switchRenderer((RendererStack::Renderer)vid_api);
-
     ui->menuWindow_scale_factor->setEnabled(! checked);
     emit resizeContents(monitors[0].mon_scrnsz_x, monitors[0].mon_scrnsz_y);
+    ui->stackedWidget->switchRenderer((RendererStack::Renderer)vid_api);
+    for (int i = 1; i < MONITORS_NUM; i++) {
+        if (monitors[i].target_buffer) {
+            renderers[i]->show();
+            renderers[i]->switchRenderer((RendererStack::Renderer)vid_api);
+            QApplication::processEvents();
+        }
+    }
 }
 
 static void
@@ -1601,6 +1626,9 @@ video_toggle_option(QAction* action, int *val)
     endblit();
     config_save();
     device_force_redraw();
+    for (int i = 0; i < MONITORS_NUM; i++) {
+        if (monitors[i].target_buffer) video_force_resize_set_monitor(1, i);
+    }
 }
 
 void MainWindow::on_actionInverted_VGA_monitor_triggered() {
@@ -1615,9 +1643,9 @@ static void update_scaled_checkboxes(Ui::MainWindow* ui, QAction* selected) {
 
     reset_screen_size();
     device_force_redraw();
-    video_force_resize_set(1);
-    for (int i = 0; i < MONITORS_NUM; i++)
-        if (monitors[i].target_buffer) atomic_flag_clear(&doresize_monitors[i]);
+    for (int i = 0; i < MONITORS_NUM; i++) {
+        if (monitors[i].target_buffer) video_force_resize_set_monitor(1, i);
+    }
     config_save();
 }
 
@@ -1796,7 +1824,6 @@ void MainWindow::on_actionChange_contrast_for_monochrome_display_triggered() {
 
 void MainWindow::on_actionForce_4_3_display_ratio_triggered() {
     video_toggle_option(ui->actionForce_4_3_display_ratio, &force_43);
-    video_force_resize_set(1);
 }
 
 void MainWindow::on_actionRemember_size_and_position_triggered()
diff --git a/src/thread.cpp b/src/thread.cpp
index 6a7af25b8..67bf8d5e6 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -26,6 +26,7 @@ thread_create(void (*thread_rout)(void *param), void *param)
 int
 thread_wait(thread_t *arg)
 {
+    if (!arg) return 0;
     auto thread = reinterpret_cast<std::thread*>(arg);
     thread->join();
     return 0;
diff --git a/src/video/video.c b/src/video/video.c
index 16eab9986..9bf810df3 100644
--- a/src/video/video.c
+++ b/src/video/video.c
@@ -943,7 +943,7 @@ video_monitor_init(int index)
     monitors[index].mon_pal_lookup = calloc(sizeof(uint32_t), 256);
     monitors[index].mon_cga_palette = calloc(1, sizeof(int));
     if (index >= 1) ui_init_monitor(index);
-    thread_create(blit_thread, monitors[index].mon_blit_data_ptr);
+    monitors[index].mon_blit_data_ptr->blit_thread = thread_create(blit_thread, monitors[index].mon_blit_data_ptr);
 }
 
 void
@@ -960,6 +960,8 @@ video_monitor_close(int monitor_index)
     free(monitors[monitor_index].mon_blit_data_ptr);
     if (!monitors[monitor_index].mon_pal_lookup_static) free(monitors[monitor_index].mon_pal_lookup);
     if (!monitors[monitor_index].mon_cga_palette_static) free(monitors[monitor_index].mon_cga_palette);
+    destroy_bitmap(monitors[monitor_index].target_buffer);
+    monitors[monitor_index].target_buffer = NULL;
     memset(&monitors[monitor_index], 0, sizeof(monitor_t));
 }