I made a very stupid error... I remembered there was another ethernet cable connected to the back of the modem before I'd changed they system and discovered it was the cable connected to the first BT...

Model : TP Link AC1900 VR900 (VDSL2 modem/router) Hardware Version : Archer VR900 v1 00000001 Firmware Version : 0.9.1 1.4 v004c.0 Build 160316 Rel.44905n ISP : BT Infinity 2 Hello, this may have...