If you want to use more than one LAN port on the hub in conjunction with the Tenda, then you need to run the hub in router mode (turn its wifi off) and connect the Tenda in access point mode, sometimes called bridge mode.
Appreciate the confirmation. I've sorted that. All works with one LAN and modem mode. I don't want two networks as it could confuse my devices or conflict. My house construction has really impacted my coverage. The Tenda Mesh system though seems to be a lot better, even just using two units. The third isn't turned in yet!
Appreciate the confirmation. I've sorted it now and the Tends works great with one LAN and modem mode. In fact I need less LAN it seems as my TV isn't experiencing connection issues at all on WiFi so no need for an ethernet cable.