I am using TP-Link _Tapo smart plugs in a laboratory environment to automate simultaneous ON/OFF control of multiple devices via a Python script using the tapo library (v0.8.7).

After updating one plug to firmware 1.4.0 or 1.4.6, the device can no longer be controlled locally. The script fails during device initialization with a Handshake1 error: 403 Forbidden, resulting in Tapo(_InvalidResponse) exceptions. This occurs even though the device is reachable on the network and responds to IP-level connectivity tests.

The setup is intended for local LAN-based automation across multiple smart plugs for synchronized experimental control. The issue appears to be specific to newer firmware versions, as older firmware devices continue to function correctly.

The failure prevents reliable local automation and suggests that firmware 1.4.6 may have changed or restricted the local API authentication mechanism.  

Failure is also present in firmware 1.4.0 Build 251020 Rel 161559

I am looking to determine if it is still possible to control the P110 Smartplug via a python script.

Any assistance or pointers to workarounds would be very welcome.

Best regards