Jira service desk login page is hang when Iptables IP whitelist

[Bao Vu]

I am getting a problem with Jira Service Desk:
I installed my Jira Service Desk(within MySQL DB locally) on CentOS Linux OS 7.5, Microsoft Azure Cloud. Iptables and default Azure firewall was used as
firewall.
When I set allow all firewall policy, I can access and use Jira Service Desk normally.
But when I set whitelist my company IP(allow all ports), block all of another IP, Login page was hanging around 1 hours.
Hope your diagnosion for this problem!