It seems not possible to have a graphical prompt for sudo credentials when launching an application requiring it (e.g: synaptic). The application simply won't launch. Environment is lumina 1.6.2 on Xubuntu Focal 20.04 LTS.
Since you closed this, did you figure this out? If so I'd like to know what the issue is so I can document it for other users in case they run into it.
It seems not possible to have a graphical prompt for sudo credentials when launching an application requiring it (e.g: synaptic). The application simply won't launch. Environment is lumina 1.6.2 on Xubuntu Focal 20.04 LTS.