Good Day, I ask you to focus your attention on the known issue, see below: security.debian.org/debian-security bullseye Release does not have a Release file .. that happens with apt-get update command. This is a bug: a system cannot update himself. I think you agree the fact that it is not possible give motivation to the user about this, but the only possible action is a new update of debian 11 that fix this behaviour.
*Can you give me the correct address in which forward this mail, if this is not the right place?* Regards Italo Canepa