I can confirm the remedie of removing all other users except one from the sudo group (see psychotrain65 from 2020-06-14):
I had two users as sudo. I removed them alternately. As long as I had only one user in sudo everything worked as expected. It did not matter which user. As soon as two users were in sudo the admin-user action failed.
I can confirm the remedie of removing all other users except one from the sudo group (see psychotrain65 from 2020-06-14):
I had two users as sudo. I removed them alternately. As long as I had only one user in sudo everything worked as expected. It did not matter which user. As soon as two users were in sudo the admin-user action failed.
Why does Lubuntu support one user in sudo only?