@lotusgary Hello, 

If app hangs on "connecting to smart plug", make sure phone is connected to the default SSID ' TP-LINK__XXXX' in set up process or device could not be found by Kasa APP. This default SSID has no Internet and it will disappear after device is installed successfully. 

• Turn off VPN settings on your phone 
• Manually Connect to TPLINK _ Smart XXX SSID when the app guides to connect to smart Wi-Fi, and go back to Kasa app

iOS: Go to the Settings page, click on the Wi-Fi option to connect to the Kasa Cam’s Wi-Fi manually.

Android: Go to the Settings page to connect to the Kasa Cam’s Wi-Fi network. Once it’s connected, please go back to the Kasa app and click on "Try Again".)

•  for IOS14 and above, enable Local network Permission for Kasa app 

https://www.tp-link.com/support/faq/2937/

• Try a different phone
• reset smart plug with the FAQ and add plug again:https://www.tp-link.com/support/faq/2648/

May I know the model and OS of your phone, did HS100 V1 work fine before, thanks.