***
Unlike in x11 (or plasma <6) , a script with zenity pop-up window doesn't work as expected: it does what it should do, but without pop-up and freezing the pc while it is working
***

SUMMARY

I have a script like the following:

#!/bin/bash
mount /some-path/some-device
if mount | grep -q ' on /some-path/some-device'; 
then
(
# =================================================================
echo "15"
echo "# fermo il server" ; sleep 2
sudo systemctl stop mariadb
sudo -u duns env DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus copyq exit
# =================================================================
echo "25"
echo "# sincro i browsers" ; sleep 2
some commands
# =================================================================
echo "50"
echo "# sincro i dati di schede" ; sleep 2
sudo rsync -r -t -p -o -g -v --delete -l -s -X  some-paths some-other-paths
# =================================================================
echo "75"
echo "# riavvio il server" ; sleep 2
sudo systemctl restart mariadb
# =================================================================
echo "90"
echo "# smonto il pen-drive" ; sleep 2
umount /some-path/some-device
sudo -u duns env DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus copyq &
# =================================================================
echo "# fatto!" ; sleep 2
echo "100"
) |
zenity --progress \
  --title="sync in progress" \
  --text="syncing..." \
  --percentage=0 
#  --auto-close 
#  --auto-kill  
# (( $? != 0 )) && zenity --error --text="Error in zenity command."
# exit 0
# zenity --info \
#     --text="<span size=\"x-large\">schede sincronizzate TO!</span>" \
#     --title="You did it!"
# #   --display=:0.0 
else 
zenity --info \
    --text="<span size=\"x-large\">inserire il pen-drive!</span>" \
    --title="manca!"
fi

STEPS TO REPRODUCE
1. Run a script with zenity from *desktop menu*
2. The script runs, but without pop-up window and freezing the PC
3. After doing "its duty" all return normal

OBSERVED RESULT

No zenity pop-up window and pc temporary freezing 

EXPECTED RESULT

Pop-up window and PC normally working

SOFTWARE/OS VERSIONS
Operating System: KDE neon 6.0
KDE Plasma Version: 6.0.2
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2
Kernel Version: 6.5.0-26-generic (64-bit)
Graphics Platform: Wayland
Processors: 4 × AMD Ryzen 3 3200G with Radeon Vega Graphics
Memory: 5,5 GiB of RAM
Graphics Processor: AMD Radeon Vega 8 Graphics

ADDITIONAL INFORMATION

Starting from terminal it is all ok.