At today, 13 of october of 2020, the stable release of debian is 'buster'.
I tried to ask my serve which is the current release and it's surprising
cat /etc/issue Debian GNU/Linux bullseye/sid \n \l Why did this happens? Can I safely return to buster stable and how ? How to avoid to go to an unstable release? Could it be happened doing a apt dist-upgrade?
deb http://ftp.debian.org/debian unstable main contrib