diff --git a/examples/simple_secure_chat_ui/main.cpp b/examples/simple_secure_chat_ui/main.cpp
index 7d9963760..cfc37515f 100644
--- a/examples/simple_secure_chat_ui/main.cpp
+++ b/examples/simple_secure_chat_ui/main.cpp
@@ -293,8 +293,12 @@ void msgstore_load_dm(const uint8_t* pub_key) {
     int p2 = line.indexOf('|', p1 + 1);
     if (p1 < 1 || p2 < p1 + 2) continue;
     uint32_t ts = (uint32_t) line.substring(0, p1).toInt();
+    if (ts == 0) continue;                   // skip unsync'd entries
     char dir = line.charAt(p1 + 1);
+    if (dir != '>' && dir != '<') continue;  // skip malformed direction
     String text = line.substring(p2 + 1);
+    text.trim();
+    if (text.length() == 0) continue;        // skip empty messages
     char time_buf[16];
     format_time(ts, time_buf, sizeof(time_buf));
     uiManager->addPrivateChatBubble(time_buf, text.c_str(), dir == '>');
@@ -315,9 +319,13 @@ void msgstore_load_public() {
     int p3 = line.indexOf('|', p2 + 1);
     if (p1 < 1 || p2 < p1 + 2 || p3 < p2 + 2) continue;
     uint32_t ts = (uint32_t) line.substring(0, p1).toInt();
+    if (ts == 0) continue;
     String sender = line.substring(p1 + 1, p2);
     char dir = line.charAt(p2 + 1);
+    if (dir != '>' && dir != '<') continue;
     String text = line.substring(p3 + 1);
+    text.trim();
+    if (text.length() == 0) continue;
     char time_buf[16];
     format_time(ts, time_buf, sizeof(time_buf));
     uiManager->addChatBubble(time_buf, sender.c_str(), text.c_str(), dir == '>');
diff --git a/examples/simple_secure_chat_ui/uiManager.cpp b/examples/simple_secure_chat_ui/uiManager.cpp
index 6b67a532f..0fe91389e 100644
--- a/examples/simple_secure_chat_ui/uiManager.cpp
+++ b/examples/simple_secure_chat_ui/uiManager.cpp
@@ -1181,7 +1181,13 @@ void UIManager::ui_Screen1_screen_init(void)
         .scrollable(false)
         .clickable(true)
         .raw();
-    lv_obj_remove_style_all(ui_DimOverlay);             // no border/padding
+    // Remove only border/padding — do NOT use remove_style_all because it also
+    // resets width/height (style props in LVGL8) back to 100×100 default,
+    // which causes the white-square artifact when night mode activates.
+    lv_obj_set_style_border_width(ui_DimOverlay, 0, 0);
+    lv_obj_set_style_outline_width(ui_DimOverlay, 0, 0);
+    lv_obj_set_style_shadow_width(ui_DimOverlay, 0, 0);
+    lv_obj_set_style_pad_all(ui_DimOverlay, 0, 0);
     lv_obj_clear_flag(ui_DimOverlay, LV_OBJ_FLAG_SCROLL_CHAIN_HOR);
     lv_obj_clear_flag(ui_DimOverlay, LV_OBJ_FLAG_SCROLL_CHAIN_VER);
 
@@ -1348,12 +1354,14 @@ void UIManager::ui_Screen1_screen_init(void)
 }
 
 void UIManager::setNightMode(bool night) {
-
     if (!ui_DimOverlay) return;
+    if (night == night_mode_active) return;   // debounce — avoids LVGL redraw every second
+    night_mode_active = night;
     if (night) {
-        lv_obj_set_style_bg_opa(ui_DimOverlay, 192, 0);  // 75% dark
+        lv_obj_set_style_bg_color(ui_DimOverlay, lv_color_black(), 0);  // explicit black
+        lv_obj_set_style_bg_opa(ui_DimOverlay, 192, 0);   // 75% dark
     } else {
-        lv_obj_set_style_bg_opa(ui_DimOverlay, 0, 0);    // none
+        lv_obj_set_style_bg_opa(ui_DimOverlay, 0, 0);     // invisible
     }
 }
 
diff --git a/include/uiManager.h b/include/uiManager.h
index 26a8c2b87..828a8ad41 100644
--- a/include/uiManager.h
+++ b/include/uiManager.h
@@ -73,6 +73,7 @@ class UIManager {
     char currentContactName[32] = {0};
     uint8_t currentContactPubKey[32] = {0};
     bool hasCurrentContact = false;
+    bool night_mode_active = false;
     char myNodeName[32] = {0};
 
     lv_obj_t* ui_ContactStatus = nullptr;