I have a Nokia Lumia 1520, which I love, but dread bringing with me when running. So, I bought a Lumia 735, which has a perfect size for a run, and I love this one too, despite the obvious omision of Glance… Anyhow, I’ve found that it often has an Internet connection issue, and if I’m not wrong, it always happens, after I’ve been on WiFi. I might have a few bars in 4G, but still I can’t connect. Eventually I tried switching to Flight Mode and back, and voila, it fixed the issue… 🙂
UPDATE: The issue is also to be found with Lumia 830 and 930.