I was able to solve this error. I don’t know but this error is only visible in Ubuntu and in some specific Networks. Below is the set of Command I used to get around the error.
sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1
sudo sysctl -w net.ipv6.conf.default.disable_ipv6=1
balena push fleet_name -m
sudo sysctl -w net.ipv6.conf.all.disable_ipv6=0
sudo sysctl -w net.ipv6.conf.default.disable_ipv6=0