Whe I use the 'kasa' command line, my Tapo L920 gives the following response. The 'removed' comments are mine, the actual response includes correct details for those values. 

Other kasa/tapo devices on my network respond correctly. 

% kasa

== Authentication failed for device ==
    == Discovery Result ==
    Device Type:        SMART.TAPOBULB
    Device Model:       L920-5(EU)
    IP:                 10.0.1.221
    MAC:                {removed}
    Device Id (hash):   {removed}
    Owner (hash):       {removed}
    HW Ver:             None
    Supports IOT Cloud: True
    OBD Src:            tplink
    Factory Default:    False
    Encrypt Type:       KLAP
    Supports HTTPS:     False
    HTTP Port:          80
    LV (Login Level):   2

% kasa --host 10.0.1.221 --type lightstrip
Got error: SmartDeviceException("Unable to connect to the device: 10.0.1.221:9999: [Errno 61] Connect call failed ('10.0.1.221', 9999)")