In the last couple of weeks, my Galaxy S 5 has been having problems with the wifi and bluetooth when they are both turned on. If the bluetooth is on, the wifi will not connect or if does connect drops it. I have tried on my home router, my mifi or at friends houses. If I don't have the bluetooth on it works fine. It has happened not on 1 phone but 2. I did a warranty swap out. Since getting the replacement phone I have even done a factory reset.