I had two KL110 bulbs working on a  schedule for front porch. Sunset to Sunrise. I set them up about 3 or 4 years ago. 

I had to reset my internet recently. Found the bulbs not working. 

No problem I thought you reinstall on Kasa app. I could get the bulbs reset, then connected with Iphone but after firmware update they would not show on app. Tried many ways and even reset router.

This is an Xfinity Xfi      router. I had upgraded to this a couple of years ago.

I finally used the xfinity app on my iphone to look at the status of devices on wiFi.   What i found is that once 

the KL 110 finished set and connected to the 2.4 gig network, The router would automatically pause. 

I could only see this easily on the app. It is on the web page control on the router but is buried several menus down.

I "Unpaused" the smart bulb using the xfinity app then the device showed up on my Kasa app.

I completed the schedule setup with no problems. I had looked everywhere when troubleshooting this and never saw it mentioned. 

I don't think it is a setting in the Xfinity router as I have not had any problem connecting any other devices.

Thought I would post it here to help others.