Pressing calculator key generates infinitely many key-press key-release events

Full description is posted in this AskUbuntu question: https://askubuntu.com/q/1336575/625814

I've got a new notebook HP Omen 15, manufactured in 2020. I has Calculator key, this key is actual normal media key.

Pressing on it launches calculator only once, after the OS is booted. No reaction for other presses.

If I run xev and press Calculator I see infinitely many messages about pressing and releasing XF86Calculator key:

...
KeyRelease event, serial 42, synthetic NO, window 0x3e00001,
root 0x29e, subw 0x0, time 52918, (151,-96), root:(151,806),
state 0x14, keycode 148 (keysym 0x1008ff1d, XF86Calculator), same_screen YES,
XLookupString gives 0 bytes:
XFilterEvent returns: False

KeyPress event, serial 42, synthetic NO, window 0x3e00001,
root 0x29e, subw 0x0, time 52918, (151,-96), root:(151,806),
state 0x14, keycode 148 (keysym 0x1008ff1d, XF86Calculator), same_screen YES,
XLookupString gives 0 bytes:
XmbLookupString gives 0 bytes:
XFilterEvent returns: False

KeyRelease event, serial 42, synthetic NO, window 0x3e00001,
root 0x29e, subw 0x0, time 52958, (151,-96), root:(151,806),
state 0x14, keycode 148 (keysym 0x1008ff1d, XF86Calculator), same_screen YES,
XLookupString gives 0 bytes:
XFilterEvent returns: False

KeyPress event, serial 42, synthetic NO, window 0x3e00001,
root 0x29e, subw 0x0, time 52958, (151,-96), root:(151,806),
state 0x14, keycode 148 (keysym 0x1008ff1d, XF86Calculator), same_screen YES,
XLookupString gives 0 bytes:
XmbLookupString gives 0 bytes:
XFilterEvent returns: False

KeyRelease event, serial 42, synthetic NO, window 0x3e00001,
root 0x29e, subw 0x0, time 52999, (151,-96), root:(151,806),
state 0x14, keycode 148 (keysym 0x1008ff1d, XF86Calculator), same_screen YES,
XLookupString gives 0 bytes:
XFilterEvent returns: False
...

Then I press Ctrl-C to stop this stream.
This happens only once after the system is booted, next runs of xev don't show any events after pressing this key.

If I run showkey, it always shows scan codes and key codes for that key:

$ sudo showkey -s
kb mode was ?UNKNOWN?
[ if you are trying this under X, it might not work
since the X server is also reading /dev/console ]

press any key (program terminates 10s after last keypress)...
0x9c
0xe0 0x21
0x1d
^Ccaught signal 2, cleaning up...
0xe0 0x21
$ sudo showkey -k
kb mode was ?UNKNOWN?
[ if you are trying this under X, it might not work
since the X server is also reading /dev/console ]

press any key (program terminates 10s after last keypress)...
keycode 28 release
keycode 140 press
keycode 29 press
^Ccaught signal 2, cleaning up...

Debugging with evtest shows that this key doesn't generate any events, while some other keys do:

sudo evtest
No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0: Power Button
/dev/input/event1: Lid Switch
/dev/input/event2: Power Button
/dev/input/event3: AT Translated Set 2 keyboard
/dev/input/event4: Video Bus
/dev/input/event5: HP WMI hotkeys
/dev/input/event6: HDA NVidia HDMI/DP,pcm=3
/dev/input/event7: SONiX USB Keyboard
/dev/input/event8: SONiX USB Keyboard Consumer Control
/dev/input/event9: SONiX USB Keyboard System Control
/dev/input/event10: PixArt Dell MS116 USB Optical Mouse
/dev/input/event11: HDA NVidia HDMI/DP,pcm=7
/dev/input/event12: HDA NVidia HDMI/DP,pcm=8
/dev/input/event13: HDA NVidia HDMI/DP,pcm=9
/dev/input/event14: HDA NVidia HDMI/DP,pcm=10
/dev/input/event15: HDA NVidia HDMI/DP,pcm=11
/dev/input/event16: SYNA32A5:00 06CB:CE17 Mouse
/dev/input/event17: SYNA32A5:00 06CB:CE17 Touchpad
/dev/input/event18: HD-Audio Generic Mic
/dev/input/event19: HD-Audio Generic Headphone
/dev/input/event20: HP Wide Vision HD Camera: HP Wi
/dev/input/event21: WI-XB400 (AVRCP)
Select the device event number [0-21]: 5
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x0 product 0x0 version 0x0
Input device name: "HP WMI hotkeys"
Supported events:
Event type 0 (EV_SYN)
Event type 1 (EV_KEY)
Event code 138 (KEY_HELP)
Event code 141 (KEY_SETUP)
Event code 148 (KEY_PROG1)
Event code 153 (KEY_DIRECTION)
Event code 184 (KEY_F14)
Event code 185 (KEY_F15)
Event code 186 (KEY_F16)
Event code 187 (KEY_F17)
Event code 224 (KEY_BRIGHTNESSDOWN)
Event code 225 (KEY_BRIGHTNESSUP)
Event code 226 (KEY_MEDIA)
Event code 240 (KEY_UNKNOWN)
Event code 358 (KEY_INFO)
Event type 4 (EV_MSC)
Event code 4 (MSC_SCAN)
Event type 5 (EV_SW)
Event code 1 (SW_TABLET_MODE) state 0
Event code 5 (SW_DOCK) state 0
Properties:
Testing ... (interrupt to exit)
Event: time 1621804159.221294, type 4 (EV_MSC), code 4 (MSC_SCAN), value 21a7
Event: time 1621804159.221294, type 1 (EV_KEY), code 186 (KEY_F16), value 1
Event: time 1621804159.221294, -------------- SYN_REPORT ------------
Event: time 1621804159.221328, type 1 (EV_KEY), code 186 (KEY_F16), value 0
Event: time 1621804159.221328, -------------- SYN_REPORT ------------
Event: time 1621804168.961868, type 4 (EV_MSC), code 4 (MSC_SCAN), value 21a5
Event: time 1621804168.961868, type 1 (EV_KEY), code 185 (KEY_F15), value 1
Event: time 1621804168.961868, -------------- SYN_REPORT ------------
Event: time 1621804168.961910, type 1 (EV_KEY), code 185 (KEY_F15), value 0
Event: time 1621804168.961910, -------------- SYN_REPORT ------------
Event: time 1621804176.067436, type 4 (EV_MSC), code 4 (MSC_SCAN), value 21a4
Event: time 1621804176.067436, type 1 (EV_KEY), code 184 (KEY_F14), value 1
Event: time 1621804176.067436, -------------- SYN_REPORT ------------
Event: time 1621804176.067460, type 1 (EV_KEY), code 184 (KEY_F14), value 0
Event: time 1621804176.067460, -------------- SYN_REPORT ------------
Event: time 1621804177.250432, type 4 (EV_MSC), code 4 (MSC_SCAN), value 21a9
Event: time 1621804177.250432, type 1 (EV_KEY), code 187 (KEY_F17), value 1
Event: time 1621804177.250432, -------------- SYN_REPORT ------------
Event: time 1621804177.250455, type 1 (EV_KEY), code 187 (KEY_F17), value 0
Event: time 1621804177.250455, -------------- SYN_REPORT ------------

Here I've pressed calculator key and Fn + some other keys, no events were on pressing calculator key.

I've got debugging and programming experience, so I'm ready to produce additional information about my system and participate in fixing this bug.