My Note 4 no longer says that it is fast charging while using my Verizon fast charger. I'm not sure if it just hides it now, or if it isn't working properly. I restarted my phone and it says it when I plug it in, then all of the sudden it dissappears. It seems like it still works but I am confused about it. When I unplug it and plug it back in, the fast charge notification doesn't show up. How am I supposed to tell if its working?