Not possible to choose which admin should enter password

Environment Ubuntu 20.04 fully upgraded.

Pretty low likelihood but if a system has more than one admin, when a user (admin or not) needs to perform an action that require administration permission a pop up cames on and require a password for a specific admin user, usually the first historically created, and it's not possible to choose another admin, a couple of examples.

1 - I would like to create a new admin and get rid of the old one, see attachment
I downloaded a pre-cooked ubuntu version to test it
- as osboxes.org I created user Luca (admin)
- logout and login as Luca
- open settings and get rid of osboxes.org

Expected: the window should ask password for my user, since I'm admin, or should let me choose which admin should enter the password to confirm
Actual: the window ask me for osboxes.org password, no chance to change user

2 - Use case see in office - A computer has 1 normal account and 2 admins account
This person have not admin priviledges so that to make some actions is require to enter admin password. Two admins are me (Luca) and an other one (Ale)
Sometimes happens that if system ask for a specific user, and user is not in the office is not possible to proceed this way.

Of course no issue in acting via command line for every action, but it's a bad UX and somtimes could happen in a worst situation.