All devices just disappeared from the app i tried to click on a schedule for a bulb and then all devices were gone All it says is: No Devices yet what happened? how to restore all the devices? I tried

I just installed 2 KD110s Kasa Doorbells. Both are Hardware Version 3.0. One is Firmware Version 2.3.15 and the other is 2.3.18.The one at 2.3.18 has an option for uPnP. What is that for? Why hasn't t