Hello,
the client must be pingable otherwise you will be missing rules to permit that.
If you get no respond form hosts behind the client while your rules allow the access, check this two points:
Does the default route at the host you try to reach point to VPN client?
If it doesn't you need a route at the host to direct the traffic to the VPN client or you activate NAT for VPN traffic at the client.
Ensure that the hosts software firewall allow access. E.g. Windows firewall drops packets from unknown private networks.