@Sn0wmiser Hello,
Sorry for the delay, Kasa camera flashing green means camera was able to connected to Wi-Fi but failed to connect to cloud server.
It could be related to modem or router's firewall or router's DNS settings.
Please refer to 'Case 3 System LED is flashing green ' in the guide below to troubleshoot and see if that works for you.
https://www.tp-link.com/support/faq/2663/
If the above does not work, please let us know the steps you have tried, and help confirm some details here:
May I know the model of your wifi router a photo of the Error message on Kasa app:
How about your network topology:
Model of your phone and its IOS / Android version:
Tapo app version