Xset issues with multimonitor setup

One of my terminals has 3 monitors.
PC has 3 hdmi ports built in.

I have the problem that the monitors wont stay dim when set in power-settings.
Powers settings uses xset to dim or switch off the monitors afte a period of time, so I had to check if xset is the culprit, and indeed it is.

As a test, running

sleep 5 ; xset dpms force off

switches all three monitors off, but after a few seconds the right hand side one switches on again, and that wakes up the rest.

Is there any way to resolve this ? as I cannot figure out why xset allows a wake up signal other than keyboard or mouse, which must be the problem.

How can I force xset to only react to keyboard and mouse for wakeup.

$ cat /etc/*relea*
NAME="MX"
VERSION="21.3_ahs (Wildflower)"
ID="mx"
VERSION_ID="21.3"
PRETTY_NAME="MX 21.3_ahs (Wildflower)"
ANSI_COLOR="0;34"
HOME_URL="https://mxlinux.org"
BUG_REPORT_URL="https://mxlinux.org"
PRETTY_NAME="MX 21.3 Wildflower"
DISTRIB_ID=MX
DISTRIB_RELEASE=21.3
DISTRIB_CODENAME="Wildflower"
DISTRIB_DESCRIPTION="MX 21.3 Wildflower"
PRETTY_NAME="Debian GNU/Linux 11 (bullseye)"
NAME="Debian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

xset -q

 xset q
Keyboard Control:
  auto repeat:  on    key click percent:  0    LED mask:  00000000
  XKB indicators:
    00: Caps Lock:   off    01: Num Lock:    off    02: Scroll Lock: off
    03: Compose:     off    04: Kana:        off    05: Sleep:       off
    06: Suspend:     off    07: Mute:        off    08: Misc:        off
    09: Mail:        off    10: Charging:    off    11: Shift Lock:  off
    12: Group 2:     off    13: Mouse Keys:  off
  auto repeat delay:  500    repeat rate:  20
  auto repeating keys:  00ffffffdffffbbf
                        fadfffefffedffff
                        9fffffffffffffff
                        fff7ffffffffffff
  bell percent:  50    bell pitch:  400    bell duration:  100
Pointer Control:
  acceleration:  2/1    threshold:  4
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  0    cycle:  0
Colors:
  default colormap:  0x20    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
  /usr/share/fonts/X11/misc,/usr/share/fonts/X11/100dpi/:unscaled,/usr/share/fonts/X11/75dpi/:unscaled,/usr/share/fonts/X11/Type1,/usr/share/fonts/X11/100dpi,/usr/share/fonts/X11/75dpi,built-ins
DPMS (Energy Star):
  Standby: 7200    Suspend: 7200    Off: 7200
  DPMS is Disabled