This should be the limitation of Windows machine if the L2TP/IPsec server (Peplink router in this case) is behind a NAT device. If your Balance router is behind a NAT device, please refer to the URL link below to modify the Windows registry.
This should be the limitation of Windows machine if the L2TP/IPsec server (Peplink router in this case) is behind a NAT device. If your Balance router is behind a NAT device, please refer to the URL link below to modify the Windows registry.