Synaptics Touchpad Disabled Upon Laptop Close

I'm a new Kubuntu user...

Host: HP-Pavilion-17-Notebook-PC Kernel: 5.15.0-60-generic x86_64
Distro: Ubuntu 22.04.2 LTS (Jammy Jellyfish)
Desktop: KDE Plasma 5.24.7

and whenever I close my laptop lid, my Synaptics TouchPad becomes disabled, although the keyboard works fine. I can CTRL+ALT+T to get to the terminal and enable my touchpad with:

xinput -enable "SynPS/2 Synaptics TouchPad"
(To find the name or ID number of the touchpad on your system, run the command "xinput list")

To automate this, I tried placing a script in /usr/lib/systemd/system-sleep/, in a file is named "20_touchpad_enable"

#!/bin/sh

# if script was called with the parameter value "post" (meaning system has just resumed after sleep)
if [ "${1}" = "post" ]; then

    # enable the touchpad
    xinput -enable "SynPS/2 Synaptics TouchPad"

    # append to a log file in will's temp folder noting that the script has run
    echo ""post"" sleep event occurred at $(date)…" >>  /home/will/Documents/_temp/wake_from_sleep.txt
fi

Unfortunately, this does NOT work, even though I can tell from my log file that the script runs whenever I open the laptop's lid or resume from sleep.

I tried installing the Synaptics drivers (sudo apt install xserver-xorg-input-synaptics), but the behavior was the same, even though I gained much finer control over the touchpad's configuration in (GUI) System Settings > Hardware > Input Devices > Touchpad

Several forum posts suggest reloading the psmouse module, but this doesn't work for me:

sudo modprobe -r psmouse && sudo modprobe psmouse

Does anyone have suggestions on how to prevent this from happening, or if not, how to automate my fix?

Here's my xinput list:

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ ELAN Touchscreen                          id=9    [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=12   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Power Button                              id=8    [slave  keyboard (3)]
    ↳ HP Truevision HD: HP Truevision           id=10   [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=11   [slave  keyboard (3)]
    ↳ Wireless hotkeys                          id=13   [slave  keyboard (3)]
    ↳ HP WMI hotkeys                            id=14   [slave  keyboard (3)]

Thank you!