Cannot access network from Docker container - linux

Question

The gist of the issue is that if I create and run a docker container (from any image, I tried many) the container does not have network access beyond the default bridge Docker creates; even when using IP addresses (not URLs/names).
I.e.
docker run --rm -it busybox ping 8.8.8.8 hangs/fails for not having accessing the network
docker run --rm -it busybox ping 172.17.0.1 also fails (note that 172.17.0.1 is docker0's IP on the host and also the gateway set by docker in the container)
if I create two containers I can ping either one from the other fine
N.B:
I have two Ubuntu hosts (same version) both running Docker 19.03.6. On one of them (dev machine) I don't have the issue (it works just fine), on the other one I do. Which means it is most likely not an OS and/or Docker version issue but some sort of misconfiguration.
It is not the DNS issue asked in most questions I could find. In fact, it is not a DNS issue at all. It presents itself when I use direct IP addresses as well as with URLs.
I use iptables on the host; these are the rules on the one where it does not work (they are different on the dev machine where networking works fine but I cannot set the here the same):
Chain INPUT (policy DROP)
target prot opt source destination
f2b-postfix-sasl tcp -- anywhere anywhere multiport dports smtp,urd,submission,imap3,imaps,pop3,pop3s
f2b-sshd tcp -- anywhere anywhere multiport dports ssh
fail2ban-ssh tcp -- anywhere anywhere multiport dports ssh
fail2ban-ssh tcp -- anywhere anywhere multiport dports ssh
ACCEPT all -- anywhere anywhere
ACCEPT all -- anywhere anywhere ctstate RELATED,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:ssh
ACCEPT tcp -- anywhere anywhere tcp dpt:http
ACCEPT tcp -- anywhere anywhere tcp dpt:https
ACCEPT icmp -- anywhere anywhere icmp echo-request
ACCEPT udp -- anywhere anywhere udp spt:ntp state ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:imap2 state NEW,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:imaps state NEW,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:urd state NEW,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:urd state NEW,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:submission state NEW,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:smtp state NEW,ESTABLISHED
Chain FORWARD (policy DROP)
target prot opt source destination
DOCKER-USER all -- anywhere anywhere
DOCKER-ISOLATION-STAGE-1 all -- anywhere anywhere
ACCEPT all -- anywhere anywhere ctstate RELATED,ESTABLISHED
DOCKER all -- anywhere anywhere
ACCEPT all -- anywhere anywhere
ACCEPT all -- anywhere anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT udp -- anywhere anywhere udp dpt:ntp state NEW,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp spt:imap2 state ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp spt:imaps state ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:urd state ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp spt:smtp state ESTABLISHED
Chain DOCKER (1 references)
target prot opt source destination
Chain DOCKER-ISOLATION-STAGE-1 (1 references)
target prot opt source destination
DOCKER-ISOLATION-STAGE-2 all -- anywhere anywhere
RETURN all -- anywhere anywhere
Chain DOCKER-ISOLATION-STAGE-2 (1 references)
target prot opt source destination
DROP all -- anywhere anywhere
RETURN all -- anywhere anywhere
Chain DOCKER-USER (1 references)
target prot opt source destination
RETURN all -- anywhere anywhere
Chain f2b-postfix-sasl (1 references)
target prot opt source destination
RETURN all -- anywhere anywhere
Chain f2b-sshd (1 references)
target prot opt source destination
RETURN all -- anywhere anywhere
Chain fail2ban-ssh (2 references)
target prot opt source destination
RETURN all -- anywhere anywhere
RETURN all -- anywhere anywhere
I am not sure what else to add for clarification.
What should I do?