It is possible that the firewall on CentOS is blocking the ICMP Ping requests.
To check if there is a rule in place, you can run (as sudo)
You want to look at the chain labeled INPUT and see what policy is set. If it is set to DENY, then unless there is a rule specifically allowing ping requests, it will get dropped.
To quickly disable the firewall to check if this is the issue, you can run (as sudo)
iptables -P INPUT ACCEPT. But be warned, this will allow everything in without an explicit rule denying it. You can set the policy back to drop after troubleshooting
iptables -P INPUT DROP.
To allow ping to be responded to, you will need to add a new rule such as described here: https://www.cyberciti.biz/tips/linux-iptables-9-allow-icmp-ping.html
But these changes will exist only until next reboot unless you have a method for maintaining persistent iptables rules across reboots.