diff --git a/gui/backend/src/cmd/interval.rs b/gui/backend/src/cmd/interval.rs
index c3d991b..ca0bce5 100644
--- a/gui/backend/src/cmd/interval.rs
+++ b/gui/backend/src/cmd/interval.rs
@@ -20,7 +20,7 @@ static INTERVAL_ID: AtomicU64 = AtomicU64::new(0);
 /// The callback fn cannot return a Result, so write only error log.
 #[tauri::command]
 pub async fn restart_interval(app: AppHandle) {
-    tracing::trace!("`restart_interval` was called.");
+    tracing::debug!("`restart_interval` was called.");
     let id = INTERVAL_ID.load(Ordering::Acquire);
     if id != 0 {
         clear_interval(id).await;
@@ -34,8 +34,8 @@ pub async fn restart_interval(app: AppHandle) {
 
     let id = set_interval(
         move || {
-            // Callbacks in the interval may survive until program termination in the worst case.
-            // Therefore, they become 'static' and must be cloned.
+            tracing::debug!("`restart_interval` closure was called.");
+
             let app = app.clone();
             let address = config.address;
             let window = app.get_webview_window("main").unwrap();
diff --git a/gui/backend/src/cmd/mod.rs b/gui/backend/src/cmd/mod.rs
index 2cf9a2b..5d9cc79 100644
--- a/gui/backend/src/cmd/mod.rs
+++ b/gui/backend/src/cmd/mod.rs
@@ -1,9 +1,9 @@
 mod config;
-mod interval;
 mod supports;
 mod system_tray;
 
 pub(super) mod device_watcher;
+pub(super) mod interval;
 
 use crate::err_log_to_string;
 use tauri::{Builder, Wry};
diff --git a/gui/backend/src/cmd/system_tray.rs b/gui/backend/src/cmd/system_tray.rs
index b98078c..fc1dbc5 100644
--- a/gui/backend/src/cmd/system_tray.rs
+++ b/gui/backend/src/cmd/system_tray.rs
@@ -5,13 +5,12 @@ use tauri::image::Image;
 ///
 /// # Panics
 /// 0 <= battery_level <= 100
+#[tracing::instrument(level = "trace")]
 pub fn update_tray_inner(
     device_name: &str,
     battery_level: u64,
     is_connected: bool,
 ) -> tauri::Result<()> {
-    tracing::debug!("Change to {battery_level} battery icon");
-
     let battery_icon = if is_connected {
         match battery_level {
             0 => include_bytes!("../../icons/battery/battery-0.png"),
diff --git a/gui/backend/src/setup/mod.rs b/gui/backend/src/setup/mod.rs
index 51a92db..e7a95ab 100644
--- a/gui/backend/src/setup/mod.rs
+++ b/gui/backend/src/setup/mod.rs
@@ -3,7 +3,10 @@ mod window_event;
 
 use self::tray_menu::new_tray_menu;
 use self::window_event::window_event;
-use crate::{cmd::device_watcher::restart_device_watcher_inner, err_log};
+use crate::{
+    cmd::{device_watcher::restart_device_watcher_inner, interval::restart_interval},
+    err_log,
+};
 use tauri::{Builder, Manager, Wry};
 pub use tray_menu::TRAY_ICON;
 
@@ -23,6 +26,7 @@ impl SetupsRegister for Builder<Wry> {
             tauri::async_runtime::spawn(async move {
                 let app = app;
                 err_log!(restart_device_watcher_inner(&app).await);
+                restart_interval(app).await;
             });
 
             Ok(())