My wife and I have been suffering this same problem for a couple of weeks, coincidentally since we had a software update. After trying all the remedies we've found on Google and failing, this morning I've found the problem that caused this for us and it was self inflicted by me. A couple of weeks ago we went out all day and late into the night and because I wanted to use my phone for photos/videos I turned on power saving mode and forgot to turn it back. So we're now all sorted.
Hope this helps someone else with this same problem.