"Disable touchpad when a mouse is attached" doesn't work

 * Cinnamon version (cinnamon --version) 5.2.7
   - Please specify if you are using the daily builds PPA : No
     (https://launchpad.net/~linuxmint-daily-build-team/+archive/ubuntu/daily-builds).
 * Distribution - Mint 20.3
 * Graphics hardware *and* driver used
 
Device-1: Intel vendor: Hewlett-Packard driver: i915 v: kernel bus ID: 0000:00:02.0 
           chip ID: 8086:9a49 
           Display: x11 server: X.Org 1.20.13 driver: modesetting unloaded: fbdev,vesa 
           resolution: 1920x1080~60Hz 
           OpenGL: renderer: Mesa Intel Xe Graphics (TGL GT2) v: 4.6 Mesa 21.2.6 
           direct render: Yes 

``` * 64 bit
 * Attach ~/.xsession-errors, or /var/log/syslog

Issue
Selecting the preference "Disable touchpad when a mouse is attached," found under preferences->mouse and touchpad->touchpad, causes the touchpad to always be enabled, even when a mouse is attached.

Steps to reproduce

1. Go to Preferences->mouse and touchpad->touchpad.
2. Select the preference "Disable touchpad when a mouse is attached."
   3)Plug in a mouse.

Expected behaviour
The touchpad should be automatically disabled.

Other information
When a mouse is plugged in, inxi returns the follow information about USB devices:

USB:
  Hub: 1-0:1 info: Full speed (or root) Hub ports: 1 rev: 2.0 
  Hub: 2-0:1 info: Full speed (or root) Hub ports: 4 rev: 3.1 
  Hub: 3-0:1 info: Full speed (or root) Hub ports: 12 rev: 2.0 
  Device-1: 3-3:2 info: Primax HP Optical Mouse type: Mouse rev: 2.0 
  Device-2: 3-6:3 info: DJKANA1BIEZCRC HP Wide Vision HD Camera type: Video 
  rev: 2.0 
  Device-3: 3-7:4 info: Elan Micro ELAN:ARM-M4 type: <vendor specific> 
  rev: 2.0 
  Device-4: 3-10:5 info: Intel type: Bluetooth rev: 2.0 
  Hub: 4-0:1 info: Full speed (or root) Hub ports: 4 rev: 3.1

When I unplug the mouse and run it again, I get

USB:
  Hub: 1-0:1 info: Full speed (or root) Hub ports: 1 rev: 2.0 
  Hub: 2-0:1 info: Full speed (or root) Hub ports: 4 rev: 3.1 
  Hub: 3-0:1 info: Full speed (or root) Hub ports: 12 rev: 2.0 
  Device-1: 3-6:3 info: DJKANA1BIEZCRC HP Wide Vision HD Camera type: Video 
  rev: 2.0 
  Device-2: 3-7:4 info: Elan Micro ELAN:ARM-M4 type: <vendor specific> 
  rev: 2.0 
  Device-3: 3-10:5 info: Intel type: Bluetooth rev: 2.0 
  Hub: 4-0:1 info: Full speed (or root) Hub ports: 4 rev: 3.1 `

Configuration info, if applicable (I don't think this is applicable?)

Start by reproducing the setting through Preferences > Mouse and Touchpad > Touchpad with a USB mouse attached, then locate the Cinnamon implementation for that preference and its mouse-device detection. No source file or test is named in the issue; done means the touchpad is automatically disabled when a mouse is plugged in and enabled again when it is removed.