It’s a fairly common complaint among iPhone owners. Even in an area with good coverage, some iPhone’s don’t like LTE networks for Web access. Here are a couple of workarounds to jumpstart your 4G.
1. Go to Settings.
2. Toggle on Airplane Mode for a second or two.
3. Toggle off Airplane Mode. This can cause the radio to reset itself and reconnect over 4G.
4. Turn off 4G -- if Airplane Mode doesn’t work -- under Settings > General.
5. Tap Cellular.
5. Switch Enable LTE to Off.