I am having the same issue as others have noted on the forum. Flashing green light with no connectivity to TPLink servers on select cameras only (KC120 and EC60).

I have a KC120 that had been working perfectly fine since January. In the last month or so it randomly stopped working and I see a flashing green light on it. Nothing changed with my home network. In fact, I have 9 other Kasa devices working perfectly fine (3 KC200 cameras, multiple smart plugs and multiple smart bulbs). Not to mention many Nest products, game systems, and countless other wireless devices.

I reset the KC120 and reconfigured it multiple times, but it still does not work. I thought maybe the camera went bad, so I ordered 2 new Spot EC60 cameras.

Now, both of those brand new Spot cameras have the same exact problem. Flashing green lights all day long and they never fully connect. I have momentarily gotten them to show up in my Kasa app in the "updating firmware" state, only for that to lock up and they go back to flashing green after power cycle.

I have tried everything imaginable to troubleshoot from changing DNS, to isolating 2.4ghz wifi, disabling all firewalls/DDoS protection, smart protection, even reviewing my firewall logs for blocked entries for the MAC addresses (there is nothing), resetting and power cycling countless times. Nothing is working, meanwhile all my other Kasa devices work fine.

TP Link / Kasa, you need to figure out what is going wrong on your end. Whatever wifi controller these cams share, or maybe they're on a different cloud service than the other cameras/smart devices, something is wrong and it is not the customer's wireless home network.