diff --git a/src/gui/main_window.py b/src/gui/main_window.py
index a7bc515..e71c663 100644
--- a/src/gui/main_window.py
+++ b/src/gui/main_window.py
@@ -1144,15 +1144,23 @@ class MainWindow(ctk.CTk):
 
         # Wait for board to boot — UART if available, else config delay
         boot_delay = self._config.boot_wait_delay
-        uart_alive = (self._uart_monitor is not None
-                      and self._uart_monitor.is_running())
+        # Check both main monitor and UART window monitor
+        uart_alive = False
+        _uart_src = None  # source of latest_info
+        if self._uart_monitor and self._uart_monitor.is_running():
+            uart_alive = True
+            _uart_src = self._uart_monitor
+        elif (self._uart_window and self._uart_window.winfo_exists()
+              and self._uart_window.is_monitoring):
+            uart_alive = True
+            _uart_src = self._uart_window
         discovered_ip: str = ""
-        if uart_alive:
+        if uart_alive and _uart_src:
             self._log_message(f"  ⏳ Waiting for UART boot signal (max {boot_delay}s)...")
             elapsed = 0.0
             while elapsed < boot_delay:
-                info = self._uart_monitor.latest_info
-                if info.ip_address or info.version:
+                info = _uart_src.latest_info if hasattr(_uart_src, 'latest_info') else _uart_src.get_latest_info()
+                if info and (info.ip_address or info.version):
                     self._log_message(
                         f"  ✓ Boot detected after {elapsed:.1f}s"
                         f" (IP={info.ip_address}, Ver={info.version})"
diff --git a/src/gui/widgets.py b/src/gui/widgets.py
index c29a824..420807b 100644
--- a/src/gui/widgets.py
+++ b/src/gui/widgets.py
@@ -1190,6 +1190,12 @@ class UartMonitorWindow(ctk.CTkToplevel):
         """True if the UART monitor thread is currently running."""
         return self._monitor is not None and self._monitor.is_running()
 
+    def get_latest_info(self):
+        """Return latest parsed BootInfo from the UART monitor, or None."""
+        if self._monitor:
+            return self._monitor.latest_info
+        return None
+
     def _on_close(self) -> None:
         """Cleanup UartMonitor and destroy window."""
         if self._monitor: