You have the 21.04 Ubuntu (hirsute) release installed and you have an option to upgrade to 21.10, that is normal.
Can't you see the difference between 20.04 and 21.04?
You can check by
cat /etc/lsb-release
Upgrade Ubuntu 20.04 to 20.04.x
You have the 21.04 Ubuntu (hirsute) release installed and you have an option to upgrade to 21.10, that is normal.
Can't you see the difference between 20.04 and 21.04?
You can check by
cat /etc/lsb-release