Dell Latitude 5289 wakes-up from suspend on volume keypress, despite lid is closed

I've just installed Ubuntu 21.10 on a convertible laptop Dell Latitude 5289. Moreover, I've switched to TLP, which helps a lot in saving battery life.

Everything works fine, except for an annoying issue: it has 3 hardware buttons, and they could get pressed by mistake when the laptop is in a bag. As mentioned, even the lid is closed, the system turns on from suspend when volume up/down gets hit. Weird to say, it does'nt happen with power button.

I've already disabled all acpid signals:

root@fli:/home/fabio# grep . /sys/bus/usb/devices/*/power/wakeup
/sys/bus/usb/devices/1-7/power/wakeup:disabled
/sys/bus/usb/devices/2-4/power/wakeup:disabled
/sys/bus/usb/devices/usb1/power/wakeup:disabled
/sys/bus/usb/devices/usb2/power/wakeup:disabled

Using /etc/rc.local:

#!/bin/bash
for device in RP09 RP08 XHC
do
    if grep -q "$device.*enabled" /proc/acpi/wakeup
    then
        echo "$device" > /proc/acpi/wakeup
    fi
done

And getting to this after reboot:

root@fli:/home/fabio# acpitool -w | grep enabled
  53. LID0    S3    *enabled   platform:PNP0C0D:00
  54. PBTN    S3    *enabled   platform:PNP0C0C:00

Despite that the laptop still awakes from suspend when the hardware buttons are clicked.

I've enabled OPTIONS="--logevents" from /etc/default/acpid to get more logs, with tail -f /var/log/syslog | grep -i acpi.

On lid close down:

Jan 26 23:17:59 fli acpid: received input layer event "button/lid LID close"
Jan 26 23:17:59 fli acpid: 0 total rules matched
Jan 26 23:17:59 fli acpid: completed input layer event "button/lid LID close"
Jan 26 23:18:00 fli acpid: received input layer event "video/tabletmode TBLT 0000008A 00000001"
Jan 26 23:18:00 fli acpid: 0 total rules matched
Jan 26 23:18:00 fli acpid: completed input layer event "video/tabletmode TBLT 0000008A 00000001"
Jan 26 23:18:00 fli acpid: received netlink event " 9DBB5994-A997- 000000d0 00000000"
Jan 26 23:18:00 fli acpid: 0 total rules matched
Jan 26 23:18:00 fli acpid: completed netlink event " 9DBB5994-A997- 000000d0 00000000"
Jan 26 23:18:01 fli acpid: received netlink event " 9DBB5994-A997- 000000d0 00000000"
Jan 26 23:18:01 fli acpid: 0 total rules matched
Jan 26 23:18:01 fli acpid: completed netlink event " 9DBB5994-A997- 000000d0 00000000"

Then, clicking volume down:

Jan 26 23:18:05 fli acpid: received input layer event "button/volumedown VOLDN 00000080 00000000 K"
Jan 26 23:18:05 fli acpid: 0 total rules matched
Jan 26 23:18:05 fli acpid: completed input layer event "button/volumedown VOLDN 00000080 00000000 K"
Jan 26 23:18:05 fli acpid: received netlink event " 9DBB5994-A997- 000000d0 00000000"
Jan 26 23:18:05 fli acpid: 0 total rules matched
Jan 26 23:18:05 fli acpid: completed netlink event " 9DBB5994-A997- 000000d0 00000000"
Jan 26 23:18:07 fli acpid: received input layer event "button/lid LID open"
Jan 26 23:18:07 fli acpid: 0 total rules matched
Jan 26 23:18:07 fli acpid: completed input layer event "button/lid LID open"
Jan 26 23:18:08 fli acpid: received input layer event "video/tabletmode TBLT 0000008A 00000000"
Jan 26 23:18:08 fli acpid: 0 total rules matched
Jan 26 23:18:08 fli acpid: completed input layer event "video/tabletmode TBLT 0000008A 00000000"
Jan 26 23:18:08 fli acpid: received netlink event " 9DBB5994-A997- 000000d0 00000000"
Jan 26 23:18:08 fli acpid: 0 total rules matched
Jan 26 23:18:08 fli acpid: completed netlink event " 9DBB5994-A997- 000000d0 00000000"

Even if the lid is closed, the display turns up - not great. Any suggestion to fix it? Thanks!