Wonder if anyone can help. Recently purchased a set of TP link Deco M4 units to boost the signal. Attached one by Ethernet cable to the Sky Q router (living room), turned off the wifi via the 192 site settings, and placed the other two decos on the first floor. I created a new SSID just called 'Deco' with a new password. 

In 'router' mode, all works fine. However, others had recommended the main deco should be in 'access point' mode, and when I've tried this, the wifi range seems longer and faster. However, when in this mode, the Sky Q router loses all internet functions- so, the 'home section' disappears, you can't download programmes, no voice search, etc. Put it back to 'router' mode - all comes back.

Various things I've tried include trying to connect the Q router and deco without cable; changed the cable itself; use the wps function (connects for 30 seconds, then loses internet connection); gone into 192 settings and tried setting a static ip for the main deco); tried to set the deco as a third party router (mainly this fails, but on rare occasions it works, fails after 30 seconds). 
 

Clearly I'm blundering around here. If anyone has experienced this issue and has resolved it, I'd really appreciate a step by step idiots guide as it's driving me mad! Thanks in advance.