ok - I suspect thats budgie-polkit-dialog zooming to 100%
From another issue I’ve modified its started as follows
more /usr/share/applications/org.buddiesofbudgie.BudgiePolkit.desktop
[Desktop Entry]
Type=Application
Name=Budgie PolicyKit UI
Comment=Budgie PolicyKit Authorisation UI
Exec=sh -c ‘sleep 15 && /usr/libexec/budgie-desktop/budgie-polkit-dialog’
Terminal=false
Categories=GNOME;GTK;System;Core;
NoDisplay=true
StartupNotify=true
X-GNOME-AutoRestart=true
X-GNOME-Autostart-Notify=true
X-GNOME-Autostart-Phase=Desktop
OnlyShowIn=Budgie
After logout and login, I can run
xhost +x
gparted
The polkit dialog then displays correctly