Switching from wifi to mobile data on Samsung S6

[AC Question]

My S6 doesn't automatically switch from wifi to mobile data, when I'm out of wifi coverage. Every time I need to restart the phone to activate the mobile data. However, the other way round works fine.
Do I need to change any setting ?

 

[BooBooth]

Have you installed any third party apps which can control your data option? Just check it out. If I were you I would use factory reboot.