My Samsung G S5 can't choose wifi in 4g or wifi mode it switches on/off, what is going on?

A

AC Question

My Samsung g s 5 cant choose wifi in 4g or wifi mode it switches on/off

In 4g mode it works ok but its not fast and sometimes it breaks down and i have to restart the phone to make it work again. IN wifi mode it breaks down / changes to 4g then back to wifi and som forth. Even when im home with 250mb and 2m away from my router.