Users created via the command line cannot be displayed on users in the Control Center.
What is the output of
cat /etc/passwd | grep -i postgres
Actually, this command is displayed above my right image.
ubuntu@master:/etc/sddm.conf.d$ cat /etc/password | grep -i postgres
cat: /etc/password: No such file or directory
ubuntu@master:/etc/sddm.conf.d$
ubuntu@master:/etc/sddm.conf.d$ cat /etc/passwd | grep -i postgres
postgres:x:1001:1001::/home/postgres:/bin/bash
ubuntu@master:/etc/sddm.conf.d$
I suspect accountsservice says that this is a systemuser which is not unusual for postgres to configure its system accounts… i.e. you shouldnt be fiddling with user attributes
