Kasa Smart Plug stops working, yellow light is solid, and app says it is offline. I can replug in the plug and it works fine, but that kind of defeats the purpose. I have about 15 of these plugs and every couple of days one of them will go off line. Usually it is a differnt plug from the last time this happened. App says firmware is up to date. Any ideas on how to prevent this from re-occuring.