Okay, I have at last hopefully sorted all my HH6 problems. Really played up over the past few days since firmware update. My netgear extender that has worked seamlessly would no longer connect, failing to obtain IP address and when it diid, still no internet connection. Problems also connecting Sky box. Some other devices had great difficulty obtaing IP addresses and where they would connect easily in the past, would no longer do so.
After several resets and trying everything I know and hours wasted, ! went to PC World this afternoon and bought a Netgear Nighthawk AC1900 D7000 VDSL modem router. Set up was a dawdle and everything is working as it should.