Hotkey to toggle Automatic Brightness does not work on ASUS UX410UQK

On my laptop ASUS UX410UQK, the hotkey does not toggle automatic brightness as intended.
Below is the result I got after two (Fn + A) strokes.

$ sudo evtest
[...]
Select the device event number [0-19]: 5
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x0 product 0x0 version 0x0
Input device name: "Asus WMI hotkeys"
[...]
Testing ... (interrupt to exit)
Event: time 1635094270.706983, type 4 (EV_MSC), code 4 (MSC_SCAN), value 7a
Event: time 1635094270.706983, type 1 (EV_KEY), code 560 (KEY_ALS_TOGGLE), value 1
Event: time 1635094270.706983, -------------- SYN_REPORT ------------
Event: time 1635094270.707032, type 1 (EV_KEY), code 560 (KEY_ALS_TOGGLE), value 0
Event: time 1635094270.707032, -------------- SYN_REPORT ------------
Event: time 1635094276.299188, type 4 (EV_MSC), code 4 (MSC_SCAN), value 7a
Event: time 1635094276.299188, type 1 (EV_KEY), code 560 (KEY_ALS_TOGGLE), value 1
Event: time 1635094276.299188, -------------- SYN_REPORT ------------
Event: time 1635094276.299244, type 1 (EV_KEY), code 560 (KEY_ALS_TOGGLE), value 0
Event: time 1635094276.299244, -------------- SYN_REPORT ------------

Somehow monitor-sensor always reports the ambient light value as 400 lux, which seems incorrect.

$ monitor-sensor
    Waiting for iio-sensor-proxy to appear
+++ iio-sensor-proxy appeared
=== No accelerometer
=== Has ambient light sensor (value: 400,000000, unit: lux)
=== No proximity sensor

I have made some test with Windows 10 21H1, using this tool https://www.microsoft.com/p/sensorexplorer/9pgl3xpq1tpx
When the ambient light senor is disable via the hotkey, it always report value as 400 lux to Windows.
When the sensor is enable, the value changes as the ambient light condition changes.
It seems that in Ubuntu, the sensor is acting as it is in disable state; as observed in Windows.

So I am not sure if the key event is not registered, or if Ubuntu cannot enable the sensor.

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: udev 248.3-1ubuntu8
ProcVersionSignature: Ubuntu 5.13.0-20.20-generic 5.13.14
Uname: Linux 5.13.0-20-generic x86_64
ApportVersion: 2.20.11-0ubuntu70
Architecture: amd64
CasperMD5CheckResult: unknown
CustomUdevRuleFiles: 70-snap.gnome-calculator.rules 70-snap.firefox.rules 50-usb-ssd-trim.rules 70-snap.core.rules 70-snap.snap-store.rules 70-snap.gnome-system-monitor.rules 70-snap.gnome-logs.rules 70-snap.canonical-livepatch.rules 70-snap.gnome-characters.rules
Date: Mon Oct 25 00:45:44 2021
InstallationDate: Installed on 2018-02-15 (1347 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20180105.1)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 004: ID 8087:0a2b Intel Corp. Bluetooth wireless interface
 Bus 001 Device 003: ID 0bda:58d2 Realtek Semiconductor Corp. USB2.0 HD UVC WebCam
 Bus 001 Device 002: ID 093a:2510 Pixart Imaging, Inc. Optical Mouse
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: ASUSTeK COMPUTER INC. UX410UQK
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.13.0-20-generic root=UUID=130ff3d4-7338-4c7d-92ff-18caafab6bdc ro quiet splash vt.handoff=7
SourcePackage: systemd
UpgradeStatus: Upgraded to impish on 2021-10-21 (3 days ago)
dmi.bios.date: 04/17/2019
dmi.bios.release: 5.12
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: UX410UQK.311
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: UX410UQK
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrUX410UQK.311:bd04/17/2019:br5.12:svnASUSTeKCOMPUTERINC.:pnUX410UQK:pvr1.0:sku:rvnASUSTeKCOMPUTERINC.:rnUX410UQK:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.family: ZenBook
dmi.product.name: UX410UQK
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.