BT-HUB6 (Main router provides WIFI to one end of house) with long CAT 5 cable to TL-WR841N (which provides LAN and WIFI to the other end of house) then a short CAT5 to TL-PA4010 which uses electricity cables to kitchen TL-WPA4220 (to provide WIFI) and the garage TL-WPA4220 (to proviode WIFI).
Now I understood that the TL-WPA4220-KIT act as 'passive' extender devices which obtain their IP addresses via DHCP from the BT-HUB6 (192.168.1.254). However I suspect the TL-WPA4220's are somehow causing other devices on the house /network (like Apple TV and BT-TV YouView boxes) to take addresses in the 192.168.0.* range, and thus they won't then connect to the internet? Any ideas?