Fix the panel:
Right-click the panel → Panel → Add New Items.
- Search for and add Generic Monitor (if not already added).
- Right-click the new genmon item → Properties.
- In the Command field, enter: bash /usr/share/kali-themes/xfce4-panel-genmon-vpnip.sh (use bash explicitly for reliability).
- Uncheck the Label checkbox (or set Text to empty).
- Set Update Period to something like 3000 (3 second, 3.00) or higher to avoid overload.
- Click Close. The panel should now refresh and show your VPN IP (if connected)
remove the plugin
sudo apt purge xfce4-genmon-plugin
sudo apt autoremove xfce4-genmon-plugin
update
sudo apt update
reinstall and upgrade
sudo apt upgrade xfce4-genmon-plugin
restart the panel
xfce4-panel -r
install i3status
sudo apt install i3status
reboot