Turning off 4g (mobile data) when on wifi?

So i just got a S6 a few days ago and my 4g doesn't automatically turn off when i'm on my home wifi. It's lit up and not dimmed or greyed out and it's eating up my data. I've had the same problem when i had the S3, but fixed it by turning off the caller id app, but this time that didn't work. I also disabled the verizon navigator app, but nothing changed. What app am i supposed to turn off for my phone to automatically disable mobile data when i'm on a trusted wifi network?

There may be some apps that do that but I either do it manually or use a Tasker task to control my mobile data, keyed by a few wifi networks I regularly connect to.