We had this problem for ages at our new house since moving in last October. No-one at Sky could seem to resolve it until we had an engineer visit a couple of weeks ago. He brought a new Q box and suggested we see how that went. He also suggested that, if the problem returned, we move the wi-fi-connected printer that stood by the Q box as it may be confusing the wi-fi reception on the Q box. Sure enough the problem DID return and we moved ther printer - it's been trouble-free since.
Annoyingly, having had our Q box replaced, we lost all our recordings and we might have been OK keeping the old box and just moving the printer! No-one at Sky, in all the time we have spent trying to have the issue resolved, ever mentioned that the proximity of another piece of wi-fi kit might be the problem!
BTW, the engineer suggested NOT enabling the Q box and mini-boxes as local wi-fi hotspots (which I had done) as this may make things worse, not better.
