ok, I used to have this problem all the time all you have to do is switch ur router off then on again because there are two types of ip adresses 192.--- or 162.--- the iPhone can only connect to 192.---, most routers reset their ips for safety they might occasionally use 162.--- so all u all u have to do is reset back 2 192.--- this worked for me 100% hope this helps 🙂🙂