Please don't tell me that it's not a bug or how it is saving my battery. I am not complaining about this feature, I just need to find a way round it. I want my phone to sleep and stay connected to the wifi.
My best answer so far is to tune into a radio station using a radio app. Because it keeps streaming, the wifi is left on. However, something like an incoming call will probably switch off the app, so it's only a partial solution.