please verify below points
1. firewall policy is in place ( VPN to LAN and vice versa)
2. any policy route configured for internet routing ?
collect the below output from CLI.
diag sniffer packet any 'src host x.x.x.x and dst host y.y.y.y' 4 0
replace x.x.x.x with local system ip and y.y.y.y with remote system ip.