Sync Communication error occurred

[sshami]

I am newbie in Pfsense and setup pfsense as software in cluster with two VMs. Carp is working fine even i can see one as a master node and secondary as Backup if i restart first node second node become master so far high availability looks good.

Setup details:
1 WAN interface
1 Sync interface (Synchronize Interface)
1 Virtual IP for carp
Configured: SystemHigh Availability Sync

On the master node i am getting following error Notices :
Communications error occurred
A communications error occurred while attempting to call XMLRPC method host_firmware_version: @ 2021-04-25 00:03:09
A communications error occurred while attempting to call XMLRPC method host_firmware_version: @ 2021-04-25 00:03:10

Other question is how to verify my sync is working properly, i thought to create one user on master node but its not automatically sync new user to backup node even firewall rules.

[sshami]

@sshami I can't ping backup Sync intrerface IP from Master node.