I use 3 accesspoints to get coverage of my house and garden. Mobile devices roaming and switch over to the AP with the best signal. Well all do except, guess it, Lumia 1520 with build 86. So far I have tried various setups: same SSID, channel and encryption for all APs; same SSID, different channels and same encryption; different SSID, different channel and different encryption. Also after every change in the setup I deleted the known WiFi networks in my L1520 and set them up again. But no chance. The Phone always sticks with one connection and won't switch over to the better one. Even I get completely out of my WiFi coverage until it disconnect it won't pick another AP but instead switches to cellular data.
No other client (and there are a lot!) has this kind of problems.
No other client (and there are a lot!) has this kind of problems.