I have been using my tetra with openvpn as a travel router. it works great. I recently configured it with a USB modem; the Huawei E8372. It still connects to the VPN and client's traffics is routed via the VPN tunnel. The issue I am having is that the traffic for the pinneaple itself is not being routed via the tunnel. There is my routing table.
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default 192.168.100.1 128.0.0.0 UG 0 0 0 tun0
default 192.168.8.1 0.0.0.0 UG 0 0