mintupdate settings dialog visually resets Cinnamon Spice update toggles to disabled #1091

Linux Mint version: 22.3 (Cinnamon)

Package: mintupdate
Describe the bug

In mintupdate preferences, enabling the Cinnamon Spice update options under Preferences -> Packages (Cinnamon Spice updates) and Preferences -> Automation (Automatic Cinnamon Spice updates) does not persist visually in the GUI after closing and reopening the preferences window or restarting the system. The toggles immediately display as disabled (false).

However, checking the underlying dconf / gsettings keys confirms that the settings are correctly stored as true in the database. The issue appears to be a rendering or signal-binding bug in the GTK/Python UI logic when reading initial state on window creation.
Steps to reproduce

Open Update Manager (mintupdate).

Go to Preferences -> Packages and enable Cinnamon Spice updates.

Go to Preferences -> Automation and enable Automatic Cinnamon Spice updates.

Apply/Close the Preferences dialog.

Re-open Preferences (or restart mintupdate).

Expected behavior

The toggles for Cinnamon Spice updates should remain in the enabled (ON) position matching the values in GSettings.
Actual behavior

The UI switches display as disabled (OFF), even though the underlying GSettings keys remain set to true.
Diagnostic output

Querying GSettings via Python's Gio API confirms the database holds the correct state:
Bash

$ python3 -c "from gi.repository import Gio; g = Gio.Settings(schema='com.linuxmint.updates'); print('show:', g.get_boolean('show-cinnamon-updates')); print('auto:', g.get_boolean('auto-update-cinnamon-spices'))"
show: True
auto: True

Running gsettings get com.linuxmint.updates show-cinnamon-updates and auto-update-cinnamon-spices also returns true.