Deconz GUI service wont start on Debian 12 GNOME

Describe the bug

deconz GUI will not start when run as a service sudo systemctl start deconz-gui but the GUI starts okay if I run /usr/bin/deCONZ from the same terminal.

Steps to reproduce the behavior

  1. Install Debian 12 GNOME on amd64 PC (I used Index of /debian-cd/current/amd64/iso-dvd)
  2. Follow instructions on ConBee II Installation to install deconz
  3. Enable auto login so the GUI can start
  4. sudo systemctl enable deconz-gui
  5. sudo systemctl disable deconz

I also changed the http-port to 8081 in the service file sudo systemctl edit deconz-gui

Expected behavior

Deconz should start and show GUI

Environment

  • Host system: PC
  • Running method: Debian 12
  • Firmware version: 26720700
  • deCONZ version: 2.22.02
  • Device: ConBee II
  • Do you use an USB extension cable: yes
  • Is there any other USB or serial devices connected to the host system? If so: Which? Wireless mouse

deCONZ Logs

Aug 18 17:30:27 lm700 systemd[1]: deconz-gui.service: Scheduled restart job, restart counter is at 1.
Aug 18 17:30:27 lm700 systemd[1]: Stopped deconz-gui.service - deCONZ: ZigBee gateway -- GUI/REST API.
Aug 18 17:30:28 lm700 systemd[1]: Started deconz-gui.service - deCONZ: ZigBee gateway -- GUI/REST API.
Aug 18 17:30:28 lm700 systemd[1]: Starting deconz-init.service - deCONZ: ZigBee gateway -- Initialisation...
Aug 18 17:30:28 lm700 deCONZ-init.sh[31735]: cat: /sys/block/mmcblk0/device/cid: No such file or directory
Aug 18 17:30:28 lm700 deCONZ[31727]: Authorization required, but no authorization protocol specified
Aug 18 17:30:28 lm700 deCONZ[31727]: qt.qpa.xcb: could not connect to display :0
Aug 18 17:30:28 lm700 deCONZ[31727]: qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
Aug 18 17:30:28 lm700 deCONZ[31727]: This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Aug 18 17:30:28 lm700 deCONZ[31727]: Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, xcb.
Aug 18 17:30:28 lm700 deCONZ-init.sh[31728]:  stopping deconz-wifi.service
Aug 18 17:30:28 lm700 systemd[1]: deconz-gui.service: Main process exited, code=killed, status=6/ABRT
Aug 18 17:30:28 lm700 systemd[1]: deconz-gui.service: Failed with result 'signal'.
Aug 18 17:30:28 lm700 systemd[1]: Reloading.
Aug 18 17:30:28 lm700 systemd[1]: deconz-init.service: Deactivated successfully.
Aug 18 17:30:28 lm700 systemd[1]: Finished deconz-init.service - deCONZ: ZigBee gateway -- Initialisation.

This looks like deCONZ is started in a non X11 session, or the systemd service is called before X session is running?