diff --git a/src/gui/main_window.py b/src/gui/main_window.py
index 5575b3b..4045467 100644
--- a/src/gui/main_window.py
+++ b/src/gui/main_window.py
@@ -218,21 +218,16 @@ class MainWindow(ctk.CTk):
         object's perspective); the FileSelector stores both the
         absolute path (for internal use) and the relative path
         (for saving to YAML).
-
-        All attribute accesses are defensive — widgets may not exist
-        yet during construction (e.g. _port_var created in _build_serial).
         """
         if not self._config:
             return
-        # Sync IP address (may not exist yet during _build_config_panel)
+        # Sync IP address
         if self._ip_string_var:
             self._config.zynq_ip = self._ip_string_var.get()
         # Sync Xilinx Kit path
-        if hasattr(self, '_xilinx_path_var'):
-            self._config.xilinx_path = self._xilinx_path_var.get()
-        # Sync serial port (may not exist yet during _build_config_panel)
-        if hasattr(self, '_port_var'):
-            self._config.serial_port = self._port_var.get()
+        self._config.xilinx_path = self._xilinx_path_var.get()
+        # Sync serial port
+        self._config.serial_port = self._port_var.get()
         # Sync file paths from FileSelectors
         files = self._get_selected_files()
         for attr, selector in [
@@ -250,9 +245,7 @@ class MainWindow(ctk.CTk):
                 if abs_path:
                     self._config._config_path  # ensure _config_path is set
                     setattr(self._config, attr, self._config._relative_path(abs_path))
-        # Sync erase checkbox (may not exist yet)
-        if hasattr(self, '_erase_cb_var'):
-            self._config.erase_all = self._erase_cb_var.get()
+        self._config.erase_all = self._erase_cb_var.get()
 
     def _auto_save_config(self) -> None:
         """Auto-save config to disk after UI changes.
@@ -593,7 +586,6 @@ class MainWindow(ctk.CTk):
             file_types=[("ELF files", "*.elf"), ("All files", "*")],
             callback=self._on_file_selected,
         )
-        self._fsbl_selector._suppress_callback = True
         if self._config.fsbl_elf_path:
             resolved = self._config.resolve_path(self._config.fsbl_elf_path)
             self._fsbl_selector.set_relative_path(self._config.fsbl_elf_path)
@@ -607,7 +599,6 @@ class MainWindow(ctk.CTk):
             file_types=[("BIT files", "*.bit"), ("All files", "*")],
             callback=self._on_file_selected,
         )
-        self._bit_selector._suppress_callback = True
         if self._config.bootloader_bit_path:
             resolved = self._config.resolve_path(self._config.bootloader_bit_path)
             self._bit_selector.set_relative_path(self._config.bootloader_bit_path)
@@ -621,7 +612,6 @@ class MainWindow(ctk.CTk):
             file_types=[("ELF files", "*.elf"), ("All files", "*")],
             callback=self._on_file_selected,
         )
-        self._elf_selector._suppress_callback = True
         if self._config.bootloader_elf_path:
             resolved = self._config.resolve_path(self._config.bootloader_elf_path)
             self._elf_selector.set_relative_path(self._config.bootloader_elf_path)
@@ -635,7 +625,6 @@ class MainWindow(ctk.CTk):
             file_types=[("BIN files", "*.bin"), ("All files", "*")],
             callback=self._on_file_selected,
         )
-        self._bootloader_bin_selector._suppress_callback = True
         if self._config.bootloader_bin_path:
             resolved = self._config.resolve_path(self._config.bootloader_bin_path)
             self._bootloader_bin_selector.set_relative_path(self._config.bootloader_bin_path)
@@ -671,21 +660,12 @@ class MainWindow(ctk.CTk):
             file_types=[("BIN files", "*.bin"), ("All files", "*")],
             callback=self._on_file_selected,
         )
-        self._firmware_bin_selector._suppress_callback = True
         if self._config.firmware_bin_path:
             resolved = self._config.resolve_path(self._config.firmware_bin_path)
             self._firmware_bin_selector.set_relative_path(self._config.firmware_bin_path)
             self._firmware_bin_selector.set_path(str(resolved))
         self._firmware_bin_selector.grid(row=8, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)
 
-        # Enable callbacks now that all selectors are created
-        for sel in (self._fsbl_selector, self._bit_selector, self._elf_selector,
-                     self._bootloader_bin_selector, self._firmware_bin_selector):
-            sel._suppress_callback = False
-
-        # Now sync and save config (all selectors exist)
-        self._auto_save_config()
-
         # Save button
         save_btn = ctk.CTkButton(
             panel,
diff --git a/src/gui/widgets.py b/src/gui/widgets.py
index 2ef172e..3e1b846 100644
--- a/src/gui/widgets.py
+++ b/src/gui/widgets.py
@@ -528,7 +528,6 @@ class FileSelector(ctk.CTkFrame):
         self._full_path: str = ""           # absolute path (internal)
         self._relative_path: str = ""       # relative path (synced to Config)
         self._display_text = ctk.StringVar(value="")
-        self._suppress_callback: bool = False  # True during construction
 
         self._create_widgets(label_text)
 
@@ -591,7 +590,7 @@ class FileSelector(ctk.CTkFrame):
         """
         self._full_path = path
         self._display_text.set(os.path.basename(path) if path else "")
-        if self._callback and not self._suppress_callback:
+        if self._callback:
             self._callback(path)
 
     def set_relative_path(self, path: str) -> None:
@@ -607,7 +606,7 @@ class FileSelector(ctk.CTkFrame):
         if path:
             self._full_path = path  # caller should resolve before calling
         self._display_text.set(os.path.basename(path) if path else "")
-        if self._callback and not self._suppress_callback:
+        if self._callback:
             self._callback(path)
 
     def get_path(self) -> str: