I just did a factory reset on my LG G2, running android 5.0.2  It goes in into the dreaded "obtaining IP address loop", and will not connect to my wi-fi router. I tried a static IP address. It connected, but refused to get any internet connectivity.  This has all been working for many years with this and other devices. None of which are experiencing any difficulties.  It was working fine prior to the factory reset.  It does get a 4G mobile connection and otherwise appears to be operating normally. No  changes made to router. power cycled the router. everything else still connected just fine. Don't ever remember this issue with this phone previously.  Something with the factory reset.....