Firewalld prevents ES nodes from communicating

I have 2 servers with CENTOS 7 installed, i have configured ElasticSearch cluster accordingly but after starting the ES instance with firewalld enabled, both nodes couldn't communicate with each other (unicast), however, when i disabled the firewalld service, everything was good.
Note: I have opened both port 9200 and 9300 on firewalld.
Any hints?

Are sure 100% sure that ports 9200/9300 are available between both machines?

Yes, both ports are opened on both firewalls