VPN Tunnel Between Balance 20x and Sierra RV50X

Im have trouble with seeing traffic between two modems.
I have IPsec VPN setup at both location, and on the VPN profile it shows connected.
on the peplink side, I have a Vlan on port 4 and one computer on the network.
for testing purpose, i have another computer on the RV50x network, trying to ping the computer on the peplink modem site. it always request time out.
im wondering, if i miss anything on the configuration.
any help is appreciated.