Help s5 won't switch between WiFi & 4g

[Android Question]

Sorry if this has been covered. Since the new lollipop update my galaxy s5 doesn't automatically switch to 3g/4g when I have been connected to WiFi? I have to restart my phone to get a connection. Is this a known glitch or my phone?

 

[EarlyMon]

A lot of people have said that turning off smart switch helps a lot.